重新导入obi

Assets/Obi/Scripts/Common.meta

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Assets/Obi/Scripts/Common/Actors.meta

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Assets/Obi/Scripts/Common/Actors/IObiParticleCollection.cs

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+using UnityEngine;
+using System.Collections;
+
+namespace Obi
+{
+    // Interface for classes that hold a collection of particles. Contains method to get common particle properties.
+    public interface IObiParticleCollection 
+    {
+        int particleCount { get; }
+        int activeParticleCount { get; }
+        bool usesOrientedParticles { get; }
+
+        int GetParticleRuntimeIndex(int index); // returns solver or blueprint index, depending on implementation.
+        Vector3 GetParticlePosition(int index);
+        Quaternion GetParticleOrientation(int index);
+        void GetParticleAnisotropy(int index, ref Vector4 b1, ref Vector4 b2, ref Vector4 b3);
+        float GetParticleMaxRadius(int index);
+        Color GetParticleColor(int index);
+    }
+}

Assets/Obi/Scripts/Common/Actors/IObiParticleCollection.cs.meta

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Assets/Obi/Scripts/Common/Actors/ObiActor.cs.meta

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Assets/Obi/Scripts/Common/Backends.meta

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Assets/Obi/Scripts/Common/Backends/Burst.meta

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Assets/Obi/Scripts/Common/Backends/Burst/BurstBackend.cs

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+#if (OBI_BURST && OBI_MATHEMATICS && OBI_COLLECTIONS)
+using UnityEngine;
+using Unity.Jobs;
+using Unity.Mathematics;
+using Unity.Collections;
+using System;
+using System.Collections;
+
+namespace Obi
+{
+    public class BurstBackend : IObiBackend
+    {
+#region Solver
+        public ISolverImpl CreateSolver(ObiSolver solver, int capacity)
+        {
+            return new BurstSolverImpl(solver);
+        }
+        public void DestroySolver(ISolverImpl  solver)
+        {
+            if (solver != null)
+                solver.Destroy();
+        }
+#endregion
+
+    }
+}
+#endif

Assets/Obi/Scripts/Common/Backends/Burst/BurstBackend.cs.meta

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Assets/Obi/Scripts/Common/Backends/Burst/BurstIntegration.cs

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+#if (OBI_BURST && OBI_MATHEMATICS && OBI_COLLECTIONS)
+
+using Unity.Mathematics;
+using System.Runtime.CompilerServices;
+
+namespace Obi
+{
+    public static class BurstIntegration
+    {
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static float4 IntegrateLinear(float4 position, float4 velocity, float dt)
+        {
+            return position + velocity * dt;
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static float4 DifferentiateLinear(float4 position, float4 prevPosition, float dt)
+        {
+            return (position - prevPosition) / dt;
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static quaternion AngularVelocityToSpinQuaternion(quaternion rotation, float4 angularVelocity, float dt)
+        {
+            var delta = new quaternion(angularVelocity.x,
+                                       angularVelocity.y,
+                                       angularVelocity.z, 0);
+
+            return new quaternion(0.5f * math.mul(delta,rotation).value * dt); 
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static quaternion IntegrateAngular(quaternion rotation, float4 angularVelocity, float dt)
+        {
+            rotation.value += AngularVelocityToSpinQuaternion(rotation,angularVelocity, dt).value;
+            return math.normalize(rotation);
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static float4 DifferentiateAngular(quaternion rotation, quaternion prevRotation, float dt)
+        {
+            return new float4((math.mul(rotation, math.inverse(prevRotation)).value * 2.0f / dt).xyz, 0);
+        }
+    }
+}
+#endif

Assets/Obi/Scripts/Common/Backends/Burst/BurstIntegration.cs.meta

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Assets/Obi/Scripts/Common/Backends/Burst/BurstJobHandle.cs

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+#if (OBI_BURST && OBI_MATHEMATICS && OBI_COLLECTIONS)
+using Unity.Jobs;
+
+namespace Obi
+{
+    public class BurstJobHandle : IObiJobHandle
+    {
+        private JobHandle handle = new JobHandle();
+
+        public BurstJobHandle SetHandle(JobHandle newHandle)
+        {
+            handle = newHandle;
+            return this;
+        }
+
+        public void Complete()
+        {
+            handle.Complete();
+        }
+
+        public void Release()
+        {
+            handle = new JobHandle();
+        }
+    }
+}
+#endif
+

Assets/Obi/Scripts/Common/Backends/Burst/BurstJobHandle.cs.meta

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Assets/Obi/Scripts/Common/Backends/Burst/BurstMath.cs

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+#if (OBI_BURST && OBI_MATHEMATICS && OBI_COLLECTIONS)
+using System;
+using System.Collections.Generic;
+using UnityEngine;
+using Unity.Collections;
+using Unity.Jobs;
+using Unity.Mathematics;
+using Unity.Burst;
+using System.Runtime.CompilerServices;
+using Unity.Collections.LowLevel.Unsafe;
+
+namespace Obi
+{
+    public static class BurstMath
+    {
+
+        public const float epsilon = 0.0000001f;
+        public const float zero = 0;
+        public const float one = 1;
+        public static readonly float golden = (math.sqrt(5.0f) + 1) / 2.0f;
+
+        // multiplies a column vector by a row vector.
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static float3x3 multrnsp(float4 column, float4 row)
+        {
+            return new float3x3(column[0] * row[0], column[0] * row[1], column[0] * row[2],
+                                column[1] * row[0], column[1] * row[1], column[1] * row[2],
+                                column[2] * row[0], column[2] * row[1], column[2] * row[2]);
+        }
+
+        // multiplies a column vector by a row vector.
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static float4x4 multrnsp4(float4 column, float4 row)
+        {
+            return new float4x4(column[0] * row[0], column[0] * row[1], column[0] * row[2], 0,
+                                column[1] * row[0], column[1] * row[1], column[1] * row[2], 0,
+                                column[2] * row[0], column[2] * row[1], column[2] * row[2], 0,
+                                0, 0, 0, 1);
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static float4 project(this float4 vector, float4 onto)
+        {
+            float len = math.lengthsq(onto);
+            if (len < epsilon)
+                return float4.zero;
+            return math.dot(onto, vector) * onto / len;
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static float4x4 TransformInertiaTensor(float4 tensor, quaternion rotation)
+        {
+            float4x4 rotMatrix = rotation.toMatrix();
+            return math.mul(rotMatrix, math.mul(tensor.asDiagonal(), math.transpose(rotMatrix)));
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static float RotationalInvMass(float4x4 inverseInertiaTensor, float4 point, float4 direction)
+        {
+            float4 cr = math.mul(inverseInertiaTensor, new float4(math.cross(point.xyz, direction.xyz), 0));
+            return math.dot(math.cross(cr.xyz, point.xyz), direction.xyz);
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static float4 GetParticleVelocityAtPoint(float4 position, float4 prevPosition, float4 point, float dt)
+        {
+            // no angular velocity, so calculate and return linear velocity only:
+            return BurstIntegration.DifferentiateLinear(position, prevPosition, dt);
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static float4 GetParticleVelocityAtPoint(float4 position, float4 prevPosition, quaternion orientation, quaternion prevOrientation, float4 point, float dt)
+        {
+            // calculate both linear and angular velocities:
+            float4 linearVelocity = BurstIntegration.DifferentiateLinear(position, prevPosition, dt);
+            float4 angularVelocity = BurstIntegration.DifferentiateAngular(orientation, prevOrientation, dt);
+            return linearVelocity + new float4(math.cross(angularVelocity.xyz, (point - prevPosition).xyz), 0);
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static float4 GetRigidbodyVelocityAtPoint(int rigidbodyIndex,
+                                                         float4 point,
+                                                         NativeArray<BurstRigidbody> rigidbodies,
+                                                         NativeArray<float4> linearDeltas,
+                                                         NativeArray<float4> angularDeltas,
+                                                         BurstAffineTransform solverToWorld) 
+        {
+            float4 linear  = rigidbodies[rigidbodyIndex].velocity + linearDeltas[rigidbodyIndex];
+            float4 angular = rigidbodies[rigidbodyIndex].angularVelocity + angularDeltas[rigidbodyIndex];
+            float4 r = solverToWorld.TransformPoint(point) - rigidbodies[rigidbodyIndex].com;
+
+            // Point is assumed to be expressed in solver space. Since rigidbodies are expressed in world space, we need to convert the
+            // point to world space, and convert the resulting velocity back to solver space.
+            return solverToWorld.InverseTransformVector(linear + new float4(math.cross(angular.xyz, r.xyz), 0));
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static float4 GetRigidbodyVelocityAtPoint(int rigidbodyIndex,
+                                                         float4 point,
+                                                         NativeArray<BurstRigidbody> rigidbodies,
+                                                         BurstAffineTransform solverToWorld)
+        {
+            float4 linear = rigidbodies[rigidbodyIndex].velocity;
+            float4 angular = rigidbodies[rigidbodyIndex].angularVelocity;
+            float4 r = solverToWorld.TransformPoint(point) - rigidbodies[rigidbodyIndex].com;
+
+            // Point is assumed to be expressed in solver space. Since rigidbodies are expressed in world space, we need to convert the
+            // point to world space, and convert the resulting velocity back to solver space.
+            return solverToWorld.InverseTransformVector(linear + new float4(math.cross(angular.xyz, r.xyz), 0));
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ApplyImpulse(int rigidbodyIndex,
+                                        float4 impulse,
+                                        float4 point,
+                                        NativeArray<BurstRigidbody> rigidbodies,
+                                        NativeArray<float4> linearDeltas,
+                                        NativeArray<float4> angularDeltas,
+                                        BurstAffineTransform solverToWorld)
+        {
+            float4 impulseWS = solverToWorld.TransformVector(impulse);
+            float4 r = solverToWorld.TransformPoint(point) - rigidbodies[rigidbodyIndex].com;
+            linearDeltas[rigidbodyIndex]  += rigidbodies[rigidbodyIndex].inverseMass * impulseWS;
+            angularDeltas[rigidbodyIndex] += math.mul(rigidbodies[rigidbodyIndex].inverseInertiaTensor, new float4(math.cross(r.xyz, impulseWS.xyz), 0));
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void ApplyDeltaQuaternion(int rigidbodyIndex,
+                                                quaternion rotation,
+                                                quaternion delta,
+                                                NativeArray<float4> angularDeltas,
+                                                BurstAffineTransform solverToWorld,
+                                                float dt)
+        {
+            quaternion rotationWS = math.mul(solverToWorld.rotation, rotation);
+            quaternion deltaWS = math.mul(solverToWorld.rotation, delta);
+
+            // convert quaternion delta to angular acceleration:
+            quaternion newRotation = math.normalize(new quaternion(rotationWS.value + deltaWS.value));
+            angularDeltas[rigidbodyIndex] += BurstIntegration.DifferentiateAngular(newRotation, rotationWS, dt);
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void OneSidedNormal(float4 forward, ref float4 normal)
+        {
+            float dot = math.dot(normal.xyz, forward.xyz);
+            if (dot < 0) normal -= 2 * dot * forward;
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static float EllipsoidRadius(float4 normSolverDirection, quaternion orientation, float3 radii)
+        {
+            float3 localDir = math.mul(math.conjugate(orientation), normSolverDirection.xyz);
+            float sqrNorm = math.lengthsq(localDir / radii);
+            return sqrNorm > epsilon ? math.sqrt(1 / sqrNorm) : radii.x;
+        }
+
+        public static quaternion ExtractRotation(float4x4 matrix, quaternion rotation, int iterations)
+        {
+            float4x4 R;
+            for (int i = 0; i < iterations; ++i)
+            {
+                R = rotation.toMatrix();
+                float3 omega = (math.cross(R.c0.xyz, matrix.c0.xyz) + math.cross(R.c1.xyz, matrix.c1.xyz) + math.cross(R.c2.xyz, matrix.c2.xyz)) /
+                               (math.abs(math.dot(R.c0.xyz, matrix.c0.xyz) + math.dot(R.c1.xyz, matrix.c1.xyz) + math.dot(R.c2.xyz, matrix.c2.xyz)) + BurstMath.epsilon);
+
+                float w = math.length(omega);
+                if (w < BurstMath.epsilon)
+                    break;
+
+                rotation = math.normalize(math.mul(quaternion.AxisAngle((1.0f / w) * omega, w), rotation));
+            }
+            return rotation;
+        }
+
+        // decomposes a quaternion in swing and twist around a given axis:
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void SwingTwist(quaternion q, float3 twistAxis, out quaternion swing, out quaternion twist)
+        {
+            float dot = math.dot(q.value.xyz, twistAxis);
+            float3 p = twistAxis * dot;
+            twist = math.normalizesafe(new quaternion(p[0], p[1], p[2], q.value.w));
+            swing = math.mul(q, math.conjugate(twist));
+        }
+
+        public static float4x4 toMatrix(this quaternion q)
+        {
+            float xx = q.value.x * q.value.x;
+            float xy = q.value.x * q.value.y;
+            float xz = q.value.x * q.value.z;
+            float xw = q.value.x * q.value.w;
+
+            float yy = q.value.y * q.value.y;
+            float yz = q.value.y * q.value.z;
+            float yw = q.value.y * q.value.w;
+
+            float zz = q.value.z * q.value.z;
+            float zw = q.value.z * q.value.w;
+
+            return new float4x4(1 - 2 * (yy + zz), 2 * (xy - zw), 2 * (xz + yw), 0,
+                                2 * (xy + zw), 1 - 2 * (xx + zz), 2 * (yz - xw), 0,
+                                2 * (xz - yw), 2 * (yz + xw), 1 - 2 * (xx + yy), 0,
+                                0, 0, 0, 1);
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static float4x4 asDiagonal(this float4 v)
+        {
+            return new float4x4(v.x, 0, 0, 0,
+                                0, v.y, 0, 0,
+                                0, 0, v.z, 0,
+                                0, 0, 0, v.w);
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static float4 diagonal(this float4x4 value)
+        {
+            return new float4(value.c0[0], value.c1[1], value.c2[2], value.c3[3]);
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static float frobeniusNorm(this float4x4 m)
+        {
+            return math.sqrt(math.lengthsq(m.c0) + math.lengthsq(m.c1) + math.lengthsq(m.c2) + math.lengthsq(m.c3));
+        }
+
+        public static void EigenSolve(float3x3 D, out float3 S, out float3x3 V)
+        {
+            // D is symmetric
+            // S is a vector whose elements are eigenvalues
+            // V is a matrix whose columns are eigenvectors
+            S = EigenValues(D);
+            float3 V0, V1, V2;
+
+            if (S[0] - S[1] > S[1] - S[2])
+            {
+                V0 = EigenVector(D, S[0]);
+                if (S[1] - S[2] < math.FLT_MIN_NORMAL)
+                {
+                    V2 = V0.unitOrthogonal();
+                }
+                else
+                {
+                    V2 = EigenVector(D, S[2]); V2 -= V0 * math.dot(V0, V2); V2 = math.normalize(V2);
+                }
+                V1 = math.cross(V2, V0);
+            }
+            else
+            {
+                V2 = EigenVector(D, S[2]);
+                if (S[0] - S[1] < math.FLT_MIN_NORMAL)
+                {
+                    V1 = V2.unitOrthogonal();
+                }
+                else
+                {
+                    V1 = EigenVector(D, S[1]); V1 -= V2 * math.dot(V2, V1); V1 = math.normalize(V1);
+                }
+                V0 = math.cross(V1, V2);
+            }
+
+            V.c0 = V0;
+            V.c1 = V1;
+            V.c2 = V2;
+        }
+
+        static float3 unitOrthogonal(this float3 input)
+        {
+            // Find a vector to cross() the input with.
+            if (!(input.x < input.z * epsilon)
+            || !(input.y < input.z * epsilon))
+            {
+                float invnm = 1 / math.length(input.xy);
+                return new float3(-input.y * invnm, input.x * invnm, 0);
+            }
+            else
+            {
+                float invnm = 1 / math.length(input.yz);
+                return new float3(0, -input.z * invnm, input.y * invnm);
+            }
+        }
+
+        // D is symmetric, S is an eigen value
+        static float3 EigenVector(float3x3 D, float S)
+        {
+            // Compute a cofactor matrix of D - sI.
+            float3 c0 = D.c0; c0[0] -= S;
+            float3 c1 = D.c1; c1[1] -= S;
+            float3 c2 = D.c2; c2[2] -= S;
+
+            // Upper triangular matrix
+            float3 c0p = new float3(c1[1] * c2[2] - c2[1] * c2[1], 0, 0);
+            float3 c1p = new float3(c2[1] * c2[0] - c1[0] * c2[2], c0[0] * c2[2] - c2[0] * c2[0], 0);
+            float3 c2p = new float3(c1[0] * c2[1] - c1[1] * c2[0], c1[0] * c2[0] - c0[0] * c2[1], c0[0] * c1[1] - c1[0] * c1[0]);
+
+            // Get a column vector with a largest norm (non-zero).
+            float C01s = c1p[0] * c1p[0];
+            float C02s = c2p[0] * c2p[0];
+            float C12s = c2p[1] * c2p[1];
+            float3 norm = new float3(c0p[0] * c0p[0] + C01s + C02s,
+                                     C01s + c1p[1] * c1p[1] + C12s,
+                                     C02s + C12s + c2p[2] * c2p[2]);
+
+            // index of largest:
+            int index = 0;
+            if (norm[0] > norm[1] && norm[0] > norm[2])
+                index = 0;
+            else if (norm[1] > norm[0] && norm[1] > norm[2])
+                index = 1;
+            else
+                index = 2;
+
+            float3 V = float3.zero;
+
+            // special case
+            if (norm[index] < math.FLT_MIN_NORMAL)
+            {
+                V[0] = 1; return V;
+            }
+            else if (index == 0)
+            {
+                V[0] = c0p[0]; V[1] = c1p[0]; V[2] = c2p[0];
+            }
+            else if (index == 1)
+            {
+                V[0] = c1p[0]; V[1] = c1p[1]; V[2] = c2p[1];
+            }
+            else
+            {
+                V = c2p;
+            }
+            return math.normalize(V);
+        }
+
+        static float3 EigenValues(float3x3 D)
+        {
+            float one_third = 1 / 3.0f;
+            float one_sixth = 1 / 6.0f;
+            float three_sqrt = math.sqrt(3.0f);
+
+            float3 c0 = D.c0;
+            float3 c1 = D.c1;
+            float3 c2 = D.c2;
+
+            float m = one_third * (c0[0] + c1[1] + c2[2]);
+
+            // K is D - I*diag(S)
+            float K00 = c0[0] - m;
+            float K11 = c1[1] - m;
+            float K22 = c2[2] - m;
+
+            float K01s = c1[0] * c1[0];
+            float K02s = c2[0] * c2[0];
+            float K12s = c2[1] * c2[1];
+
+            float q = 0.5f * (K00 * (K11 * K22 - K12s) - K22 * K01s - K11 * K02s) + c1[0] * c2[1] * c0[2];
+            float p = one_sixth * (K00 * K00 + K11 * K11 + K22 * K22 + 2 * (K01s + K02s + K12s));
+
+            float p_sqrt = math.sqrt(p);
+
+            float tmp = p * p * p - q * q;
+            float phi = one_third * math.atan2(math.sqrt(math.max(0, tmp)), q);
+            float phi_c = math.cos(phi);
+            float phi_s = math.sin(phi);
+            float sqrt_p_c_phi = p_sqrt * phi_c;
+            float sqrt_p_3_s_phi = p_sqrt * three_sqrt * phi_s;
+
+            float e0 = m + 2 * sqrt_p_c_phi;
+            float e1 = m - sqrt_p_c_phi - sqrt_p_3_s_phi;
+            float e2 = m - sqrt_p_c_phi + sqrt_p_3_s_phi;
+
+            float aux;
+            if (e0 > e1)
+            {
+                aux = e0;
+                e0 = e1;
+                e1 = aux;
+            }
+            if (e0 > e2)
+            {
+                aux = e0;
+                e0 = e2;
+                e2 = aux;
+            }
+            if (e1 > e2)
+            {
+                aux = e1;
+                e1 = e2;
+                e2 = aux;
+            }
+
+            return new float3(e2, e1, e0);
+        }
+
+        public struct CachedTri
+        {
+            public float4 vertex;
+            public float4 edge0;
+            public float4 edge1;
+            public float4 data;
+
+            public void Cache(float4 v1,
+                              float4 v2,
+                              float4 v3)
+            {
+                vertex = v1;
+                edge0 = v2 - v1;
+                edge1 = v3 - v1;
+                data = float4.zero;
+                data[0] = math.dot(edge0, edge0);
+                data[1] = math.dot(edge0, edge1);
+                data[2] = math.dot(edge1, edge1);
+                data[3] = data[0] * data[2] - data[1] * data[1];
+            }
+        }
+
+        public static float4 NearestPointOnTri(in CachedTri tri,
+                                               float4 p,
+                                               out float4 bary)
+        {
+            float4 v0 = tri.vertex - p;
+            float b0 = math.dot(tri.edge0, v0);
+            float b1 = math.dot(tri.edge1, v0);
+            float t0 = tri.data[1] * b1 - tri.data[2] * b0;
+            float t1 = tri.data[1] * b0 - tri.data[0] * b1;
+
+            if (t0 + t1 <= tri.data[3])
+            {
+                if (t0 < zero)
+                {
+                    if (t1 < zero)  // region 4
+                    {
+                        if (b0 < zero)
+                        {
+                            t1 = zero;
+                            if (-b0 >= tri.data[0])  // V0
+                                t0 = one;
+                            else  // E01
+                                t0 = -b0 / tri.data[0];
+                        }
+                        else
+                        {
+                            t0 = zero;
+                            if (b1 >= zero)  // V0
+                                t1 = zero;
+                            else if (-b1 >= tri.data[2])  // V2
+                                t1 = one;
+                            else  // E20
+                                t1 = -b1 / tri.data[2];
+                        }
+                    }
+                    else  // region 3
+                    {
+                        t0 = zero;
+                        if (b1 >= zero)  // V0
+                            t1 = zero;
+                        else if (-b1 >= tri.data[2])  // V2
+                            t1 = one;
+                        else  // E20
+                            t1 = -b1 / tri.data[2];
+                    }
+                }
+                else if (t1 < zero)  // region 5
+                {
+                    t1 = zero;
+                    if (b0 >= zero)  // V0
+                        t0 = zero;
+                    else if (-b0 >= tri.data[0])  // V1
+                        t0 = one;
+                    else  // E01
+                        t0 = -b0 / tri.data[0];
+                }
+                else  // region 0, interior
+                {
+                    float invDet = one / tri.data[3];
+                    t0 *= invDet;
+                    t1 *= invDet;
+                }
+            }
+            else
+            {
+                float tmp0, tmp1, numer, denom;
+
+                if (t0 < zero)  // region 2
+                {
+                    tmp0 = tri.data[1] + b0;
+                    tmp1 = tri.data[2] + b1;
+                    if (tmp1 > tmp0)
+                    {
+                        numer = tmp1 - tmp0;
+                        denom = tri.data[0] - 2 * tri.data[1] + tri.data[2];
+                        if (numer >= denom)  // V1
+                        {
+                            t0 = one;
+                            t1 = zero;
+                        }
+                        else  // E12
+                        {
+                            t0 = numer / denom;
+                            t1 = one - t0;
+                        }
+                    }
+                    else
+                    {
+                        t0 = zero;
+                        if (tmp1 <= zero)  // V2
+                            t1 = one;
+                        else if (b1 >= zero)  // V0
+                            t1 = zero;
+                        else  // E20
+                            t1 = -b1 / tri.data[2];
+                    }
+                }
+                else if (t1 < zero)  // region 6
+                {
+                    tmp0 = tri.data[1] + b1;
+                    tmp1 = tri.data[0] + b0;
+                    if (tmp1 > tmp0)
+                    {
+                        numer = tmp1 - tmp0;
+                        denom = tri.data[0] - 2 * tri.data[1] + tri.data[2];
+                        if (numer >= denom)  // V2
+                        {
+                            t1 = one;
+                            t0 = zero;
+                        }
+                        else  // E12
+                        {
+                            t1 = numer / denom;
+                            t0 = one - t1;
+                        }
+                    }
+                    else
+                    {
+                        t1 = zero;
+                        if (tmp1 <= zero)  // V1
+                            t0 = one;
+                        else if (b0 >= zero)  // V0
+                            t0 = zero;
+                        else  // E01
+                            t0 = -b0 / tri.data[0];
+                    }
+                }
+                else  // region 1
+                {
+                    numer = tri.data[2] + b1 - tri.data[1] - b0;
+                    if (numer <= zero)  // V2
+                    {
+                        t0 = zero;
+                        t1 = one;
+                    }
+                    else
+                    {
+                        denom = tri.data[0] - 2 * tri.data[1] + tri.data[2];
+                        if (numer >= denom)  // V1
+                        {
+                            t0 = one;
+                            t1 = zero;
+                        }
+                        else  // 12
+                        {
+                            t0 = numer / denom;
+                            t1 = one - t0;
+                        }
+                    }
+                }
+            }
+
+            bary = new float4(1 - (t0 + t1), t0, t1,0);
+            return tri.vertex + t0 * tri.edge0 + t1 * tri.edge1;
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static float4 NearestPointOnEdge(float4 a, float4 b, float4 p, out float mu, bool clampToSegment = true)
+        {
+            float4 ap = p - a;
+            float4 ab = b - a;
+
+            mu = math.dot(ap, ab) / math.dot(ab, ab);
+
+            if (clampToSegment)
+                mu = math.saturate(mu);
+
+            return a + ab * mu;
+        }
+
+        public static float4 NearestPointsTwoEdges(float4 a, float4 b, float4 c, float4 d, out float mu1, out float mu2)
+        {
+            float4 dc = d - c;
+            float lineDirSqrMag = math.dot(dc, dc);
+            float4 inPlaneA = a - (math.dot(a - c, dc) / lineDirSqrMag * dc);
+            float4 inPlaneB = b - (math.dot(b - c, dc) / lineDirSqrMag * dc);
+
+            float4 inPlaneBA = inPlaneB - inPlaneA;
+            float t = math.dot(c - inPlaneA, inPlaneBA) / math.dot(inPlaneBA, inPlaneBA);
+
+            //t = (inPlaneA != inPlaneB) ? t : 0f; // Zero's t if parallel
+            float4 segABtoLineCD = math.lerp(a, b, math.saturate(t));
+
+            float4 segCDtoSegAB = NearestPointOnEdge(c, d, segABtoLineCD, out mu1);
+            float4 segABtoSegCD = NearestPointOnEdge(a, b, segCDtoSegAB, out mu2);
+
+            return segCDtoSegAB;
+        }
+
+        public static float4 BaryCoords(in float4 A,
+                                        in float4 B,
+                                        in float4 C,
+                                        in float4 P)
+        {
+
+            // Compute vectors
+            float4 v0 = C - A;
+            float4 v1 = B - A;
+            float4 v2 = P - A;
+
+            // Compute dot products
+            float dot00 = math.dot(v0, v0);
+            float dot01 = math.dot(v0, v1);
+            float dot02 = math.dot(v0, v2);
+            float dot11 = math.dot(v1, v1);
+            float dot12 = math.dot(v1, v2);
+
+            // Compute barycentric coordinates
+            float det = dot00 * dot11 - dot01 * dot01;
+            if (math.abs(det) > epsilon)
+            {
+                float u = (dot11 * dot02 - dot01 * dot12) / det;
+                float v = (dot00 * dot12 - dot01 * dot02) / det;
+                return new float4(1 - u - v, v, u, 0);
+            }
+            return float4.zero;
+
+        }
+
+        public static float4 BaryCoords2(in float4 A,
+                                         in float4 B,
+                                         in float4 P)
+        {
+            float4 v0 = P - A;
+            float4 v1 = B - A;
+            float y = math.sqrt(math.dot(v0, v0) / (math.dot(v1, v1) + epsilon));
+            return new float4(1 - y, y, 0, 0);
+        }
+
+        public static float4 BaryIntrpl(in float4 p1, in float4 p2, in float4 p3, in float4 coords)
+        {
+            return coords[0] * p1 + coords[1] * p2 + coords[2] * p3;
+        }
+
+        public static float4 BaryIntrpl(in float4 p1, in float4 p2, in float4 coords)
+        {
+            return coords[0] * p1 + coords[1] * p2;
+        }
+
+        public static float BaryIntrpl(float p1, float p2, float p3, float4 coords)
+        {
+            return coords[0] * p1 + coords[1] * p2 + coords[2] * p3;
+        }
+
+        public static float BaryIntrpl(float p1, float p2, float4 coords)
+        {
+            return coords[0] * p1 + coords[1] * p2;
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static float BaryScale(float4 coords)
+        {
+            return 1.0f / math.dot(coords, coords);
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static float4 BarycenterForSimplexOfSize(int simplexSize)
+        {
+            float value = 1f / simplexSize;
+            float4 center = float4.zero;
+            for (int i = 0; i < simplexSize; ++i)
+                center[i] = value;
+            return center;
+        }
+
+        public static unsafe void RemoveRangeBurst<T>(this NativeList<T> list, int index, int count)
+            where T : unmanaged
+        {
+#if ENABLE_UNITY_COLLECTIONS_CHECKS
+            if ((uint)index >= (uint)list.Length)
+            {
+                throw new IndexOutOfRangeException(
+                    $"Index {index} is out of range in NativeList of '{list.Length}' Length.");
+            }
+#endif
+
+            int elemSize = UnsafeUtility.SizeOf<T>();
+            byte* basePtr = (byte*)list.GetUnsafePtr();
+
+            UnsafeUtility.MemMove(basePtr + (index * elemSize), basePtr + ((index + count) * elemSize), elemSize * (list.Length - count - index));
+
+            // No easy way to change length so we just loop this unfortunately.
+            for (var i = 0; i < count; i++)
+            {
+                list.RemoveAtSwapBack(list.Length - 1);
+            }
+        }
+    }
+}
+#endif

Assets/Obi/Scripts/Common/Backends/Burst/BurstMath.cs.meta

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Assets/Obi/Scripts/Common/Backends/Burst/Collisions.meta

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Assets/Obi/Scripts/Common/Backends/Burst/Collisions/BurstBox.cs

@@ -0,0 +1,93 @@
+#if (OBI_BURST && OBI_MATHEMATICS && OBI_COLLECTIONS)
+using Unity.Collections;
+using Unity.Mathematics;
+
+namespace Obi
+{
+    public struct BurstBox : BurstLocalOptimization.IDistanceFunction, IBurstCollider
+    {
+        public BurstColliderShape shape;
+        public BurstAffineTransform colliderToSolver;
+        public float dt;
+
+        public void Evaluate(float4 point, float4 radii, quaternion orientation, ref BurstLocalOptimization.SurfacePoint projectedPoint)
+        {
+            float4 center = shape.center * colliderToSolver.scale;
+            float4 size = shape.size * colliderToSolver.scale * 0.5f;
+
+            // clamp the point to the surface of the box:
+            point = colliderToSolver.InverseTransformPointUnscaled(point) - center;
+
+            if (shape.is2D != 0)
+                point[2] = 0;
+
+            // get minimum distance for each axis:
+            float4 distances = size - math.abs(point);
+
+            if (distances.x >= 0 && distances.y >= 0 && distances.z >= 0)
+            {
+                // find minimum distance in all three axes and the axis index:
+                float min = float.MaxValue;
+                int axis = 0;
+
+                for (int i = 0; i < 3; ++i)
+                {
+                    if (distances[i] < min)
+                    {
+                        min = distances[i];
+                        axis = i;
+                    }
+                }
+
+                projectedPoint.normal = float4.zero;
+                projectedPoint.point = point;
+
+                projectedPoint.normal[axis] = point[axis] > 0 ? 1 : -1;
+                projectedPoint.point[axis] = size[axis] * projectedPoint.normal[axis];
+            }
+            else
+            {
+                projectedPoint.point = math.clamp(point, -size, size);
+                projectedPoint.normal = math.normalizesafe(point - projectedPoint.point);
+            }
+
+            projectedPoint.point = colliderToSolver.TransformPointUnscaled(projectedPoint.point + center + projectedPoint.normal * shape.contactOffset);
+            projectedPoint.normal = colliderToSolver.TransformDirection(projectedPoint.normal);
+        }
+
+        public void Contacts(int colliderIndex,
+                             int rigidbodyIndex,
+                             NativeArray<BurstRigidbody> rigidbodies,
+
+                              NativeArray<float4> positions,
+                              NativeArray<quaternion> orientations,
+                              NativeArray<float4> velocities,
+                              NativeArray<float4> radii,
+
+                              NativeArray<int> simplices,
+                              in BurstAabb simplexBounds,
+                              int simplexIndex,
+                              int simplexStart,
+                              int simplexSize,
+
+                              NativeQueue<BurstContact>.ParallelWriter contacts,
+                              int optimizationIterations,
+                              float optimizationTolerance)
+        {
+            var co = new BurstContact() { bodyA = simplexIndex, bodyB = colliderIndex };
+            float4 simplexBary = BurstMath.BarycenterForSimplexOfSize(simplexSize);
+
+            var colliderPoint = BurstLocalOptimization.Optimize<BurstBox>(ref this, positions, orientations, radii, simplices, simplexStart, simplexSize,
+                                                        ref simplexBary, out float4 convexPoint, optimizationIterations, optimizationTolerance);
+
+            co.pointB = colliderPoint.point;
+            co.normal = colliderPoint.normal;
+            co.pointA = simplexBary;
+
+            contacts.Enqueue(co);
+        }
+
+    }
+
+}
+#endif

Assets/Obi/Scripts/Common/Backends/Burst/Collisions/BurstBox.cs.meta

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Assets/Obi/Scripts/Common/Backends/Burst/Collisions/BurstCapsule.cs

@@ -0,0 +1,73 @@
+#if (OBI_BURST && OBI_MATHEMATICS && OBI_COLLECTIONS)
+using Unity.Collections;
+using Unity.Mathematics;
+
+namespace Obi
+{
+    public struct BurstCapsule : BurstLocalOptimization.IDistanceFunction, IBurstCollider
+    {
+        public BurstColliderShape shape;
+        public BurstAffineTransform colliderToSolver;
+        public float dt;
+
+        public void Evaluate(float4 point, float4 radii, quaternion orientation, ref BurstLocalOptimization.SurfacePoint projectedPoint)
+        {
+            float4 center = shape.center * colliderToSolver.scale;
+            point = colliderToSolver.InverseTransformPointUnscaled(point) - center;
+
+            if (shape.is2D != 0)
+                point[2] = 0;
+
+            int direction = (int)shape.size.z;
+            float radius = shape.size.x * math.max(colliderToSolver.scale[(direction + 1) % 3],
+                                                   colliderToSolver.scale[(direction + 2) % 3]);
+
+            float height = math.max(radius, shape.size.y * 0.5f * colliderToSolver.scale[direction]);
+            float4 halfVector = float4.zero;
+            halfVector[direction] = height - radius;
+
+            float4 centerLine = BurstMath.NearestPointOnEdge(-halfVector, halfVector, point, out float mu);
+            float4 centerToPoint = point - centerLine;
+            float distanceToCenter = math.length(centerToPoint);
+
+            float4 normal = centerToPoint / (distanceToCenter + BurstMath.epsilon);
+
+            projectedPoint.point = colliderToSolver.TransformPointUnscaled(center + centerLine + normal * (radius + shape.contactOffset));
+            projectedPoint.normal = colliderToSolver.TransformDirection(normal);
+        }
+
+        public void Contacts(int colliderIndex,
+                             int rigidbodyIndex,
+                             NativeArray<BurstRigidbody> rigidbodies,
+
+                              NativeArray<float4> positions,
+                              NativeArray<quaternion> orientations,
+                              NativeArray<float4> velocities,
+                              NativeArray<float4> radii,
+
+                              NativeArray<int> simplices,
+                              in BurstAabb simplexBounds,
+                              int simplexIndex,
+                              int simplexStart,
+                              int simplexSize,
+
+                              NativeQueue<BurstContact>.ParallelWriter contacts,
+                              int optimizationIterations,
+                              float optimizationTolerance)
+        {
+            var co = new BurstContact() { bodyA = simplexIndex, bodyB = colliderIndex };
+            float4 simplexBary = BurstMath.BarycenterForSimplexOfSize(simplexSize);
+
+            var colliderPoint = BurstLocalOptimization.Optimize<BurstCapsule>(ref this, positions, orientations, radii, simplices, simplexStart, simplexSize,
+                                                                              ref simplexBary, out float4 convexPoint, optimizationIterations, optimizationTolerance);
+
+            co.pointB = colliderPoint.point;
+            co.normal = colliderPoint.normal;
+            co.pointA = simplexBary;
+
+            contacts.Enqueue(co);
+        }
+    }
+
+}
+#endif

Assets/Obi/Scripts/Common/Backends/Burst/Collisions/BurstCapsule.cs.meta

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Assets/Obi/Scripts/Common/Backends/Burst/Collisions/BurstColliderShape.cs

@@ -0,0 +1,25 @@
+#if (OBI_BURST && OBI_MATHEMATICS && OBI_COLLECTIONS)
+using Unity.Mathematics;
+
+namespace Obi
+{
+
+    public struct BurstColliderShape
+    {
+        public float4 center;
+        public float4 size; /**<     box: size of the box in each axis.
+                                      sphere: radius of sphere (x,y,z),
+                                      capsule: radius (x), height(y), direction (z, can be 0, 1 or 2).
+                                      heightmap: width (x axis), height (y axis) and depth (z axis) in world units.*/
+
+        public ColliderShape.ShapeType type;
+        public float contactOffset;
+        public int dataIndex;
+        public int rigidbodyIndex;  // index of the associated rigidbody in the collision world.
+        public int materialIndex;   // index of the associated material in the collision world.
+        public int filter;
+        public int flags;           // for now, only used for trigger (1) or regular collider (0).
+        public int is2D;            // whether the collider is 2D (1) or 3D (0).
+    }
+}
+#endif

Assets/Obi/Scripts/Common/Backends/Burst/Collisions/BurstColliderShape.cs.meta

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Assets/Obi/Scripts/Common/Backends/Burst/Collisions/BurstColliderWorld.cs

@@ -0,0 +1,552 @@
+#if (OBI_BURST && OBI_MATHEMATICS && OBI_COLLECTIONS)
+using UnityEngine;
+using Unity.Collections;
+using Unity.Jobs;
+using Unity.Mathematics;
+using Unity.Burst;
+
+namespace Obi
+{
+
+
+    public class BurstColliderWorld : MonoBehaviour, IColliderWorldImpl
+    {
+        struct MovingCollider
+        {
+            public BurstCellSpan oldSpan;
+            public BurstCellSpan newSpan;
+            public int entity;
+        }
+
+        private int refCount = 0;
+        private int colliderCount = 0;
+
+        private NativeMultilevelGrid<int> grid;
+        private NativeQueue<MovingCollider> movingColliders;
+        public NativeQueue<BurstContact> colliderContactQueue;
+
+        public ObiNativeCellSpanList cellSpans;
+
+        public int referenceCount { get { return refCount; } }
+
+        public void Awake()
+        {
+
+            this.grid = new NativeMultilevelGrid<int>(1000, Allocator.Persistent);
+            this.movingColliders = new NativeQueue<MovingCollider>(Allocator.Persistent);
+            this.colliderContactQueue = new NativeQueue<BurstContact>(Allocator.Persistent);
+
+            this.cellSpans = new ObiNativeCellSpanList();
+
+            ObiColliderWorld.GetInstance().RegisterImplementation(this);
+        }
+
+        public void OnDestroy()
+        {
+            ObiColliderWorld.GetInstance().UnregisterImplementation(this);
+
+            grid.Dispose();
+            movingColliders.Dispose();
+            colliderContactQueue.Dispose();
+            cellSpans.Dispose();
+        }
+
+        public void IncreaseReferenceCount()
+        {
+            refCount++;
+        }
+        public void DecreaseReferenceCount()
+        {
+            if (--refCount <= 0 && gameObject != null)
+                DestroyImmediate(gameObject);  
+        }
+
+        public void SetColliders(ObiNativeColliderShapeList shapes, ObiNativeAabbList bounds, ObiNativeAffineTransformList transforms, int count)
+        {
+            colliderCount = count;
+
+            // insert new empty cellspans at the end if needed:
+            while (colliderCount > cellSpans.count)
+                cellSpans.Add(new CellSpan(new VInt4(10000), new VInt4(10000)));
+        }
+
+        public void SetRigidbodies(ObiNativeRigidbodyList rigidbody)
+        {
+        }
+
+        public void SetCollisionMaterials(ObiNativeCollisionMaterialList materials)
+        {
+
+        }
+
+        public void SetTriangleMeshData(ObiNativeTriangleMeshHeaderList headers, ObiNativeBIHNodeList nodes, ObiNativeTriangleList triangles, ObiNativeVector3List vertices)
+        {
+        }
+
+        public void SetEdgeMeshData(ObiNativeEdgeMeshHeaderList headers, ObiNativeBIHNodeList nodes, ObiNativeEdgeList edges, ObiNativeVector2List vertices)
+        {
+        }
+
+        public void SetDistanceFieldData(ObiNativeDistanceFieldHeaderList headers, ObiNativeDFNodeList nodes) { }
+        public void SetHeightFieldData(ObiNativeHeightFieldHeaderList headers, ObiNativeFloatList samples) { }
+
+        public void UpdateWorld(float deltaTime)
+        {
+            var world = ObiColliderWorld.GetInstance();
+
+            var identifyMoving = new IdentifyMovingColliders
+            {
+                movingColliders = movingColliders.AsParallelWriter(),
+                shapes = world.colliderShapes.AsNativeArray<BurstColliderShape>(cellSpans.count),
+                rigidbodies = world.rigidbodies.AsNativeArray<BurstRigidbody>(),
+                collisionMaterials = world.collisionMaterials.AsNativeArray<BurstCollisionMaterial>(),
+                bounds = world.colliderAabbs.AsNativeArray<BurstAabb>(cellSpans.count),
+                cellIndices = cellSpans.AsNativeArray<BurstCellSpan>(),
+                colliderCount = colliderCount,
+                dt = deltaTime
+            };
+            JobHandle movingHandle = identifyMoving.Schedule(cellSpans.count, 128);
+
+            var updateMoving = new UpdateMovingColliders
+            {
+                movingColliders = movingColliders,
+                grid = grid,
+                colliderCount = colliderCount
+            };
+
+            updateMoving.Schedule(movingHandle).Complete();
+
+            // remove tail from the current spans array:
+            if (colliderCount < cellSpans.count)
+                cellSpans.count -= cellSpans.count - colliderCount;
+        }
+
+        [BurstCompile]
+        struct IdentifyMovingColliders : IJobParallelFor
+        {
+            [WriteOnly]
+            [NativeDisableParallelForRestriction]
+            public NativeQueue<MovingCollider>.ParallelWriter movingColliders;
+
+            [ReadOnly] public NativeArray<BurstColliderShape> shapes;
+            [ReadOnly] public NativeArray<BurstRigidbody> rigidbodies;
+            [ReadOnly] public NativeArray<BurstCollisionMaterial> collisionMaterials;
+            public NativeArray<BurstAabb> bounds;
+
+            public NativeArray<BurstCellSpan> cellIndices;
+            [ReadOnly] public int colliderCount;
+            [ReadOnly] public float dt;
+
+            // Iterate over all colliders and store those whose cell span has changed.
+            public void Execute(int i)
+            {
+                BurstAabb velocityBounds = bounds[i];
+
+                int rb = shapes[i].rigidbodyIndex;
+
+                // Expand bounds by rigidbody's linear velocity
+                // (check against out of bounds rigidbody access, can happen when a destroyed collider references a rigidbody that has just been destroyed too)
+                if (rb >= 0 && rb < rigidbodies.Length)
+                    velocityBounds.Sweep(rigidbodies[rb].velocity * dt);
+
+                // Expand bounds by collision material's stick distance:
+                if (shapes[i].materialIndex >= 0) 
+                    velocityBounds.Expand(collisionMaterials[shapes[i].materialIndex].stickDistance);
+
+                float size = velocityBounds.AverageAxisLength();
+                int level = NativeMultilevelGrid<int>.GridLevelForSize(size);
+                float cellSize = NativeMultilevelGrid<int>.CellSizeOfLevel(level);
+
+                // get new collider bounds cell coordinates:
+                BurstCellSpan newSpan = new BurstCellSpan(new int4(GridHash.Quantize(velocityBounds.min.xyz, cellSize), level),
+                                                          new int4(GridHash.Quantize(velocityBounds.max.xyz, cellSize), level));
+
+                // if the collider is 2D, project it to the z = 0 cells.
+                if (shapes[i].is2D != 0)
+                {
+                    newSpan.min[2] = 0;
+                    newSpan.max[2] = 0;
+                }
+
+                // if the collider is at the tail (removed), we will only remove it from its current cellspan.
+                // if the new cellspan and the current one are different, we must remove it from its current cellspan and add it to its new one.
+                if (i >= colliderCount || cellIndices[i] != newSpan)
+                {
+                    // Add the collider to the list of moving colliders:
+                    movingColliders.Enqueue(new MovingCollider()
+                    {
+                        oldSpan = cellIndices[i],
+                        newSpan = newSpan,
+                        entity = i
+                    });
+
+                    // Update previous coords:
+                    cellIndices[i] = newSpan;
+                }
+
+            }
+        }
+
+        [BurstCompile]
+        struct UpdateMovingColliders : IJob
+        {
+            public NativeQueue<MovingCollider> movingColliders;
+            public NativeMultilevelGrid<int> grid;
+            [ReadOnly] public int colliderCount;
+
+            public void Execute()
+            {
+                while (movingColliders.Count > 0)
+                {
+                    MovingCollider movingCollider = movingColliders.Dequeue();
+
+                    // remove from old cells:
+                    grid.RemoveFromCells(movingCollider.oldSpan, movingCollider.entity);
+
+                    // insert in new cells, as long as the index is below the amount of colliders.
+                    // otherwise, the collider is at the "tail" and there's no need to add it back.
+                    if (movingCollider.entity < colliderCount)
+                        grid.AddToCells(movingCollider.newSpan, movingCollider.entity);
+                }
+
+                // remove all empty cells from the grid:
+                grid.RemoveEmpty();
+            }
+        }
+
+        [BurstCompile]
+        unsafe struct GenerateContactsJob : IJobParallelFor
+        {
+            //collider grid:
+            [ReadOnly] public NativeMultilevelGrid<int> colliderGrid;
+
+            [DeallocateOnJobCompletion]
+            [ReadOnly] public NativeArray<int> gridLevels;
+
+            // particle arrays:
+            [ReadOnly] public NativeArray<float4> velocities;
+            [ReadOnly] public NativeArray<float4> positions;
+            [ReadOnly] public NativeArray<quaternion> orientations;
+            [ReadOnly] public NativeArray<float> invMasses;
+            [ReadOnly] public NativeArray<float4> radii;
+            [ReadOnly] public NativeArray<int> filters;
+
+            // simplex arrays:
+            [ReadOnly] public NativeArray<int> simplices;
+            [ReadOnly] public SimplexCounts simplexCounts;
+            [ReadOnly] public NativeArray<BurstAabb> simplexBounds;
+
+            // collider arrays:
+            [ReadOnly] public NativeArray<BurstAffineTransform> transforms;
+            [ReadOnly] public NativeArray<BurstColliderShape> shapes;
+            [ReadOnly] public NativeArray<BurstCollisionMaterial> collisionMaterials;
+            [ReadOnly] public NativeArray<BurstRigidbody> rigidbodies;
+            [ReadOnly] public NativeArray<BurstAabb> bounds;
+
+            // distance field data:
+            [ReadOnly] public NativeArray<DistanceFieldHeader> distanceFieldHeaders;
+            [ReadOnly] public NativeArray<BurstDFNode> distanceFieldNodes;
+
+            // triangle mesh data:
+            [ReadOnly] public NativeArray<TriangleMeshHeader> triangleMeshHeaders;
+            [ReadOnly] public NativeArray<BIHNode> bihNodes;
+            [ReadOnly] public NativeArray<Triangle> triangles;
+            [ReadOnly] public NativeArray<float3> vertices;
+
+            // edge mesh data:
+            [ReadOnly] public NativeArray<EdgeMeshHeader> edgeMeshHeaders;
+            [ReadOnly] public NativeArray<BIHNode> edgeBihNodes;
+            [ReadOnly] public NativeArray<Edge> edges;
+            [ReadOnly] public NativeArray<float2> edgeVertices;
+
+            // height field data:
+            [ReadOnly] public NativeArray<HeightFieldHeader> heightFieldHeaders;
+            [ReadOnly] public NativeArray<float> heightFieldSamples;
+
+            // output contacts queue:
+            [WriteOnly]
+            [NativeDisableParallelForRestriction]
+            public NativeQueue<BurstContact>.ParallelWriter contactsQueue;
+
+            // auxiliar data:
+            [ReadOnly] public BurstAffineTransform solverToWorld;
+            [ReadOnly] public BurstAffineTransform worldToSolver;
+            [ReadOnly] public float deltaTime;
+            [ReadOnly] public Oni.SolverParameters parameters;
+
+            public void Execute(int i)
+            {
+                int simplexStart = simplexCounts.GetSimplexStartAndSize(i, out int simplexSize);
+                BurstAabb simplexBoundsSS = simplexBounds[i];
+
+                // get all colliders overlapped by the cell bounds, in all grid levels:
+                BurstAabb simplexBoundsWS = simplexBoundsSS.Transformed(solverToWorld);
+                NativeList<int> candidates = new NativeList<int>(16,Allocator.Temp);
+
+                // max size of the particle bounds in cells:
+                int3 maxSize = new int3(10);
+                bool is2D = parameters.mode == Oni.SolverParameters.Mode.Mode2D;
+
+                for (int l = 0; l < gridLevels.Length; ++l)
+                {
+                    float cellSize = NativeMultilevelGrid<int>.CellSizeOfLevel(gridLevels[l]);
+
+                    int3 minCell = GridHash.Quantize(simplexBoundsWS.min.xyz, cellSize);
+                    int3 maxCell = GridHash.Quantize(simplexBoundsWS.max.xyz, cellSize);
+                    maxCell = minCell + math.min(maxCell - minCell, maxSize);
+
+                    for (int x = minCell[0]; x <= maxCell[0]; ++x)
+                    {
+                        for (int y = minCell[1]; y <= maxCell[1]; ++y)
+                        {
+                            // for 2D mode, project each cell at z == 0 and check them too. This way we ensure 2D colliders
+                            // (which are inserted in cells with z == 0) are accounted for in the broadphase.
+                            if (is2D)
+                            {
+                                if (colliderGrid.TryGetCellIndex(new int4(x, y, 0, gridLevels[l]), out int cellIndex))
+                                {
+                                    var colliderCell = colliderGrid.usedCells[cellIndex];
+                                    candidates.AddRange(colliderCell.ContentsPointer, colliderCell.Length);
+                                }
+                            }
+
+                            for (int z = minCell[2]; z <= maxCell[2]; ++z)
+                            {
+                                if (colliderGrid.TryGetCellIndex(new int4(x, y, z, gridLevels[l]), out int cellIndex))
+                                {
+                                    var colliderCell = colliderGrid.usedCells[cellIndex];
+                                    candidates.AddRange(colliderCell.ContentsPointer, colliderCell.Length);
+                                }
+                            }
+                        }
+                    }
+                }
+
+                if (candidates.Length > 0)
+                {
+                    // make sure each candidate collider only shows up once in the array:
+                    NativeArray<int> uniqueCandidates = candidates.AsArray();
+                    uniqueCandidates.Sort();
+                    int uniqueCount = uniqueCandidates.Unique();
+
+                    // iterate over candidate colliders, generating contacts for each one
+                    for (int k = 0; k < uniqueCount; ++k)
+                    {
+                        int c = uniqueCandidates[k];
+                        if (c < shapes.Length)
+                        {
+                            BurstColliderShape shape = shapes[c];
+                            BurstAabb colliderBoundsWS = bounds[c];
+                            int rb = shape.rigidbodyIndex;
+
+                            // Expand bounds by rigidbody's linear velocity:
+                            if (rb >= 0)
+                                colliderBoundsWS.Sweep(rigidbodies[rb].velocity * deltaTime);
+
+                            // Expand bounds by collision material's stick distance:
+                            if (shape.materialIndex >= 0)
+                                colliderBoundsWS.Expand(collisionMaterials[shape.materialIndex].stickDistance);
+
+                            // check if any simplex particle and the collider should collide:
+                            bool shouldCollide = false;
+                            var colliderCategory = shape.filter & ObiUtils.FilterCategoryBitmask;
+                            var colliderMask = (shape.filter & ObiUtils.FilterMaskBitmask) >> 16;
+                            for (int j = 0; j < simplexSize; ++j)
+                            {
+                                var simplexCategory = filters[simplices[simplexStart + j]] & ObiUtils.FilterCategoryBitmask;
+                                var simplexMask =    (filters[simplices[simplexStart + j]] & ObiUtils.FilterMaskBitmask) >> 16;
+                                shouldCollide |= (simplexCategory & colliderMask) != 0 && (simplexMask & colliderCategory) != 0;
+                            }
+
+                            if (shouldCollide && simplexBoundsWS.IntersectsAabb(in colliderBoundsWS, is2D))
+                            {
+                                // generate contacts for the collider:
+                                BurstAffineTransform colliderToSolver = worldToSolver * transforms[c];
+                                GenerateContacts(in shape, in colliderToSolver, c, rb, i, simplexStart, simplexSize, simplexBoundsSS);
+                            }
+                        }
+                    }
+                }
+            }
+
+            private void GenerateContacts(in BurstColliderShape shape,
+                                          in BurstAffineTransform colliderToSolver,
+                                          int colliderIndex,
+                                          int rigidbodyIndex,
+                                          int simplexIndex,
+                                          int simplexStart,
+                                          int simplexSize,
+                                          in BurstAabb simplexBoundsSS)
+            {
+                float4x4 solverToCollider;
+                BurstAabb simplexBoundsCS;
+
+                switch (shape.type)
+                {
+                    case ColliderShape.ShapeType.Sphere:
+                        BurstSphere sphereShape = new BurstSphere() { colliderToSolver = colliderToSolver, shape = shape, dt = deltaTime };
+                        sphereShape.Contacts(colliderIndex, rigidbodyIndex, rigidbodies, positions, orientations, velocities, radii, simplices, in simplexBoundsSS,
+                                             simplexIndex, simplexStart, simplexSize, contactsQueue, parameters.surfaceCollisionIterations, parameters.surfaceCollisionTolerance);
+                        break;
+                    case ColliderShape.ShapeType.Box:
+                        BurstBox boxShape = new BurstBox() { colliderToSolver = colliderToSolver, shape = shape, dt = deltaTime };
+                        boxShape.Contacts(colliderIndex, rigidbodyIndex, rigidbodies, positions, orientations, velocities, radii, simplices, in simplexBoundsSS,
+                                          simplexIndex, simplexStart, simplexSize, contactsQueue, parameters.surfaceCollisionIterations, parameters.surfaceCollisionTolerance);
+                        break;
+                    case ColliderShape.ShapeType.Capsule:
+                        BurstCapsule capsuleShape = new BurstCapsule(){colliderToSolver = colliderToSolver,shape = shape, dt = deltaTime };
+                        capsuleShape.Contacts(colliderIndex, rigidbodyIndex, rigidbodies, positions, orientations, velocities, radii, simplices, in simplexBoundsSS,
+                                              simplexIndex, simplexStart, simplexSize, contactsQueue, parameters.surfaceCollisionIterations, parameters.surfaceCollisionTolerance);
+                        break;
+                    case ColliderShape.ShapeType.SignedDistanceField:
+
+                        if (shape.dataIndex < 0) return;
+
+                        BurstDistanceField distanceFieldShape = new BurstDistanceField()
+                        {
+                            colliderToSolver = colliderToSolver,
+                            solverToWorld = solverToWorld,
+                            shape = shape,
+                            distanceFieldHeaders = distanceFieldHeaders,
+                            dfNodes = distanceFieldNodes,
+                            dt = deltaTime,
+                            collisionMargin = parameters.collisionMargin
+                        };
+
+                        distanceFieldShape.Contacts(colliderIndex, rigidbodyIndex, rigidbodies, positions, orientations, velocities, radii, simplices, in simplexBoundsSS,
+                                                    simplexIndex, simplexStart, simplexSize, contactsQueue, parameters.surfaceCollisionIterations, parameters.surfaceCollisionTolerance);
+
+                        break;
+                    case ColliderShape.ShapeType.Heightmap:
+
+                        if (shape.dataIndex < 0) return;
+
+                        // invert a full matrix here to accurately represent collider bounds scale.
+                        solverToCollider = math.inverse(float4x4.TRS(colliderToSolver.translation.xyz, colliderToSolver.rotation, colliderToSolver.scale.xyz));
+                        simplexBoundsCS = simplexBoundsSS.Transformed(solverToCollider);
+
+                        BurstHeightField heightmapShape = new BurstHeightField()
+                        {
+                            colliderToSolver = colliderToSolver,
+                            solverToWorld = solverToWorld,
+                            shape = shape,
+                            header = heightFieldHeaders[shape.dataIndex],
+                            heightFieldSamples = heightFieldSamples,
+                            collisionMargin = parameters.collisionMargin,
+                            dt = deltaTime
+                        };
+
+                        heightmapShape.Contacts(colliderIndex, rigidbodyIndex, rigidbodies, positions, orientations, velocities, radii, simplices, in simplexBoundsCS,
+                                                    simplexIndex, simplexStart, simplexSize, contactsQueue, parameters.surfaceCollisionIterations, parameters.surfaceCollisionTolerance);
+
+                        break;
+                    case ColliderShape.ShapeType.TriangleMesh:
+
+                        if (shape.dataIndex < 0) return;
+
+                        // invert a full matrix here to accurately represent collider bounds scale.
+                        solverToCollider = math.inverse(float4x4.TRS(colliderToSolver.translation.xyz, colliderToSolver.rotation, colliderToSolver.scale.xyz));
+                        simplexBoundsCS = simplexBoundsSS.Transformed(solverToCollider);
+
+                        BurstTriangleMesh triangleMeshShape = new BurstTriangleMesh()
+                        {
+                            colliderToSolver = colliderToSolver,
+                            solverToWorld = solverToWorld,
+                            shape = shape,
+                            header = triangleMeshHeaders[shape.dataIndex],
+                            bihNodes = bihNodes,
+                            triangles = triangles,
+                            vertices = vertices,
+                            collisionMargin = parameters.collisionMargin,
+                            dt = deltaTime
+                        };
+
+                        triangleMeshShape.Contacts(colliderIndex, rigidbodyIndex, rigidbodies, positions, orientations, velocities, radii, simplices, in simplexBoundsCS,
+                                                    simplexIndex, simplexStart, simplexSize, contactsQueue, parameters.surfaceCollisionIterations, parameters.surfaceCollisionTolerance);
+
+                        break;
+                    case ColliderShape.ShapeType.EdgeMesh:
+
+                        if (shape.dataIndex < 0) return;
+
+                        // invert a full matrix here to accurately represent collider bounds scale.
+                        solverToCollider = math.inverse(float4x4.TRS(colliderToSolver.translation.xyz, colliderToSolver.rotation, colliderToSolver.scale.xyz));
+                        simplexBoundsCS = simplexBoundsSS.Transformed(solverToCollider);
+
+                        BurstEdgeMesh edgeMeshShape = new BurstEdgeMesh()
+                        {
+                            colliderToSolver = colliderToSolver,
+                            shape = shape,
+                            header = edgeMeshHeaders[shape.dataIndex],
+                            edgeBihNodes = edgeBihNodes,
+                            edges = edges,
+                            vertices = edgeVertices,
+                            dt = deltaTime
+                        };
+
+                        edgeMeshShape.Contacts(colliderIndex, rigidbodyIndex, rigidbodies, positions, orientations, velocities, radii, simplices, in simplexBoundsCS,
+                                                    simplexIndex, simplexStart, simplexSize, contactsQueue, parameters.surfaceCollisionIterations, parameters.surfaceCollisionTolerance);
+
+                        break;
+                }
+            }
+
+        }
+
+
+        public JobHandle GenerateContacts(BurstSolverImpl solver, float deltaTime, JobHandle inputDeps)
+        {
+            var world = ObiColliderWorld.GetInstance();
+
+            var generateColliderContactsJob = new GenerateContactsJob
+            {
+                colliderGrid = grid,
+                gridLevels = grid.populatedLevels.GetKeyArray(Allocator.TempJob),
+
+                positions = solver.positions,
+                orientations = solver.orientations,
+                velocities = solver.velocities,
+                invMasses = solver.invMasses,
+                radii = solver.principalRadii,
+                filters = solver.filters,
+
+                simplices = solver.simplices,
+                simplexCounts = solver.simplexCounts,
+                simplexBounds = solver.simplexBounds,
+
+                transforms = world.colliderTransforms.AsNativeArray<BurstAffineTransform>(),
+                shapes = world.colliderShapes.AsNativeArray<BurstColliderShape>(),
+                rigidbodies = world.rigidbodies.AsNativeArray<BurstRigidbody>(),
+                collisionMaterials = world.collisionMaterials.AsNativeArray<BurstCollisionMaterial>(),
+                bounds = world.colliderAabbs.AsNativeArray<BurstAabb>(),
+
+                distanceFieldHeaders = world.distanceFieldContainer.headers.AsNativeArray<DistanceFieldHeader>(),
+                distanceFieldNodes = world.distanceFieldContainer.dfNodes.AsNativeArray<BurstDFNode>(),
+
+                triangleMeshHeaders = world.triangleMeshContainer.headers.AsNativeArray<TriangleMeshHeader>(),
+                bihNodes = world.triangleMeshContainer.bihNodes.AsNativeArray<BIHNode>(),
+                triangles = world.triangleMeshContainer.triangles.AsNativeArray<Triangle>(),
+                vertices = world.triangleMeshContainer.vertices.AsNativeArray<float3>(),
+
+                edgeMeshHeaders = world.edgeMeshContainer.headers.AsNativeArray<EdgeMeshHeader>(),
+                edgeBihNodes = world.edgeMeshContainer.bihNodes.AsNativeArray<BIHNode>(),
+                edges = world.edgeMeshContainer.edges.AsNativeArray<Edge>(),
+                edgeVertices = world.edgeMeshContainer.vertices.AsNativeArray<float2>(),
+
+                heightFieldHeaders = world.heightFieldContainer.headers.AsNativeArray<HeightFieldHeader>(),
+                heightFieldSamples = world.heightFieldContainer.samples.AsNativeArray<float>(),
+
+                contactsQueue = colliderContactQueue.AsParallelWriter(),
+                solverToWorld = solver.solverToWorld,
+                worldToSolver = solver.worldToSolver,
+                deltaTime = deltaTime,
+                parameters = solver.abstraction.parameters
+            };
+
+            return generateColliderContactsJob.Schedule(solver.simplexCounts.simplexCount, 16, inputDeps);
+
+        }
+
+    }
+}
+#endif

Assets/Obi/Scripts/Common/Backends/Burst/Collisions/BurstColliderWorld.cs.meta

@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: f1a161c4294214a4fbcb7e9e94800494
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/Obi/Scripts/Common/Backends/Burst/Collisions/BurstDFNode.cs

@@ -0,0 +1,65 @@
+#if (OBI_BURST && OBI_MATHEMATICS && OBI_COLLECTIONS)
+using System;
+using System.Runtime.InteropServices;
+using UnityEngine;
+using Unity.Mathematics;
+
+namespace Obi
+{
+    public struct BurstDFNode
+    {
+        public float4 distancesA;
+        public float4 distancesB;
+        public float4 center;
+        public int firstChild;
+
+        // add 12 bytes of padding to ensure correct memory alignment:
+        private int pad0;
+        private int pad1;
+        private int pad2;
+
+        public float4 SampleWithGradient(float4 position)
+        {
+            float4 nPos = GetNormalizedPos(position);
+
+            // trilinear interpolation of distance:
+            float4 x = distancesA + (distancesB - distancesA) * nPos[0];
+            float2 y = x.xy + (x.zw - x.xy) * nPos[1];
+            float distance = y[0] + (y[1] - y[0]) * nPos[2];
+
+            // gradient estimation:
+            // x == 0
+            float2 a = distancesA.xy + (distancesA.zw - distancesA.xy) * nPos[1];
+            float x0 = a[0] + (a[1] - a[0]) * nPos[2];
+
+            // x == 1
+            a = distancesB.xy + (distancesB.zw - distancesB.xy) * nPos[1];
+            float x1 = a[0] + (a[1] - a[0]) * nPos[2];
+
+            // y == 0
+            float y0 = x[0] + (x[1] - x[0]) * nPos[2];
+
+            // y == 1
+            float y1 = x[2] + (x[3] - x[2]) * nPos[2];
+
+            return new float4(x1 - x0, y1 - y0, y[1] - y[0], distance);
+
+        }
+
+        public float4 GetNormalizedPos(float4 position)
+        {
+            float4 corner = center - new float4(center[3]);
+            return (position - corner) / (center[3] * 2);
+        }
+
+        public int GetOctant(float4 position)
+        {
+            int index = 0;
+            if (position[0] > center[0]) index |= 4;
+            if (position[1] > center[1]) index |= 2;
+            if (position[2] > center[2]) index |= 1;
+            return index;
+        }
+    }
+}
+#endif

Assets/Obi/Scripts/Common/Backends/Burst/Collisions/BurstDFNode.cs.meta

@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: b5a1060edd11d4d268313295cdfe778b
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/Obi/Scripts/Common/Backends/Burst/Collisions/BurstDistanceField.cs

@@ -0,0 +1,107 @@
+#if (OBI_BURST && OBI_MATHEMATICS && OBI_COLLECTIONS)
+using Unity.Collections;
+using Unity.Mathematics;
+
+namespace Obi
+{
+    public struct BurstDistanceField : BurstLocalOptimization.IDistanceFunction, IBurstCollider
+    {
+        public BurstColliderShape shape;
+        public BurstAffineTransform colliderToSolver;
+        public BurstAffineTransform solverToWorld;
+
+        public float dt;
+        public float collisionMargin;
+
+        public NativeArray<DistanceFieldHeader> distanceFieldHeaders;
+        public NativeArray<BurstDFNode> dfNodes;
+
+        public void Evaluate(float4 point, float4 radii, quaternion orientation, ref BurstLocalOptimization.SurfacePoint projectedPoint)
+        {
+            point = colliderToSolver.InverseTransformPoint(point);
+
+            if (shape.is2D != 0)
+                point[2] = 0;
+
+            var header = distanceFieldHeaders[shape.dataIndex];
+            float4 sample = DFTraverse(point, 0, in header, in dfNodes);
+            float4 normal = new float4(math.normalize(sample.xyz), 0);
+
+            projectedPoint.point = colliderToSolver.TransformPoint(point - normal * (sample[3] - shape.contactOffset));
+            projectedPoint.normal = colliderToSolver.TransformDirection(normal);
+        }
+
+        public void Contacts(int colliderIndex,
+                             int rigidbodyIndex,
+                             NativeArray<BurstRigidbody> rigidbodies,
+
+                              NativeArray<float4> positions,
+                              NativeArray<quaternion> orientations,
+                              NativeArray<float4> velocities,
+                              NativeArray<float4> radii,
+
+                              NativeArray<int> simplices,
+                              in BurstAabb simplexBounds,
+                              int simplexIndex,
+                              int simplexStart,
+                              int simplexSize,
+
+                              NativeQueue<BurstContact>.ParallelWriter contacts,
+                              int optimizationIterations,
+                              float optimizationTolerance)
+        {
+            if (shape.dataIndex < 0) return;
+
+            var co = new BurstContact() { bodyA = simplexIndex, bodyB = colliderIndex };
+            float4 simplexBary = BurstMath.BarycenterForSimplexOfSize(simplexSize);
+
+            var colliderPoint = BurstLocalOptimization.Optimize<BurstDistanceField>(ref this, positions, orientations, radii, simplices, simplexStart, simplexSize,
+                                                                ref simplexBary, out float4 simplexPoint, optimizationIterations, optimizationTolerance);
+
+            co.pointB = colliderPoint.point;
+            co.normal = colliderPoint.normal;
+            co.pointA = simplexBary;
+
+            float4 velocity = float4.zero;
+            float simplexRadius = 0;
+            for (int j = 0; j < simplexSize; ++j)
+            {
+                int particleIndex = simplices[simplexStart + j];
+                simplexRadius += radii[particleIndex].x * simplexBary[j];
+                velocity += velocities[particleIndex] * simplexBary[j];
+            }
+
+            float4 rbVelocity = float4.zero;
+            if (rigidbodyIndex >= 0)
+                rbVelocity = BurstMath.GetRigidbodyVelocityAtPoint(rigidbodyIndex, colliderPoint.point, rigidbodies, solverToWorld);
+
+            float dAB = math.dot(simplexPoint - colliderPoint.point, colliderPoint.normal);
+            float vel = math.dot(velocity     - rbVelocity,          colliderPoint.normal);
+
+            if (vel * dt + dAB <= simplexRadius + shape.contactOffset + collisionMargin)
+                contacts.Enqueue(co);
+        }
+
+        private static float4 DFTraverse(float4 particlePosition,
+                                         int nodeIndex,
+                                         in DistanceFieldHeader header,
+                                         in NativeArray<BurstDFNode> dfNodes)
+        {
+            var node = dfNodes[header.firstNode + nodeIndex];
+
+            // if the child node exists, recurse down the df octree:
+            if (node.firstChild >= 0)
+            {
+                int octant = node.GetOctant(particlePosition);
+                return DFTraverse(particlePosition, node.firstChild + octant, in header, in dfNodes);
+            }
+            else
+            {
+                return node.SampleWithGradient(particlePosition);
+            }
+        }
+
+    }
+
+}
+#endif

Assets/Obi/Scripts/Common/Backends/Burst/Collisions/BurstDistanceField.cs.meta

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Assets/Obi/Scripts/Common/Backends/Burst/Collisions/BurstEdgeMesh.cs

@@ -0,0 +1,125 @@
+#if (OBI_BURST && OBI_MATHEMATICS && OBI_COLLECTIONS)
+using Unity.Collections;
+using Unity.Mathematics;
+
+namespace Obi
+{
+    public struct BurstEdgeMesh : BurstLocalOptimization.IDistanceFunction, IBurstCollider
+    {
+
+        public BurstColliderShape shape;
+        public BurstAffineTransform colliderToSolver;
+        public int dataOffset;
+        public float dt;
+
+        public EdgeMeshHeader header;
+        public NativeArray<BIHNode> edgeBihNodes;
+        public NativeArray<Edge> edges;
+        public NativeArray<float2> vertices;
+
+        public void Evaluate(float4 point, float4 radii, quaternion orientation, ref BurstLocalOptimization.SurfacePoint projectedPoint)
+        {
+            point = colliderToSolver.InverseTransformPointUnscaled(point);
+
+            if (shape.is2D != 0)
+                point[2] = 0;
+
+            Edge t = edges[header.firstEdge + dataOffset];
+            float4 v1 = (new float4(vertices[header.firstVertex + t.i1], 0) + shape.center) * colliderToSolver.scale;
+            float4 v2 = (new float4(vertices[header.firstVertex + t.i2], 0) + shape.center) * colliderToSolver.scale;
+
+            float4 nearestPoint = BurstMath.NearestPointOnEdge(v1, v2, point, out float mu);
+            float4 normal = math.normalizesafe(point - nearestPoint);
+
+            projectedPoint.normal = colliderToSolver.TransformDirection(normal);
+            projectedPoint.point = colliderToSolver.TransformPointUnscaled(nearestPoint + normal * shape.contactOffset);
+        }
+
+
+        public void Contacts(int colliderIndex,
+                             int rigidbodyIndex,
+                             NativeArray<BurstRigidbody> rigidbodies,
+
+                              NativeArray<float4> positions,
+                              NativeArray<quaternion> orientations,
+                              NativeArray<float4> velocities,
+                              NativeArray<float4> radii,
+
+                              NativeArray<int> simplices,
+                              in BurstAabb simplexBounds,
+                              int simplexIndex,
+                              int simplexStart,
+                              int simplexSize,
+
+                              NativeQueue<BurstContact>.ParallelWriter contacts,
+                              int optimizationIterations,
+                              float optimizationTolerance)
+        {
+            if (shape.dataIndex < 0) return;
+
+            BIHTraverse(colliderIndex, simplexIndex, simplexStart, simplexSize,
+                        positions, orientations, radii, simplices, in simplexBounds, 0, contacts, optimizationIterations, optimizationTolerance);
+        }
+
+        private void BIHTraverse(int colliderIndex,
+                                 int simplexIndex,
+                                 int simplexStart,
+                                 int simplexSize,
+                                 NativeArray<float4> positions,
+                                 NativeArray<quaternion> orientations,
+                                 NativeArray<float4> radii,
+                                 NativeArray<int> simplices,
+                                 in BurstAabb simplexBounds,
+                                 int nodeIndex,
+                                 NativeQueue<BurstContact>.ParallelWriter contacts,
+                                 int optimizationIterations,
+                                 float optimizationTolerance)
+        {
+            var node = edgeBihNodes[header.firstNode + nodeIndex];
+
+            if (node.firstChild >= 0)
+            {
+                // visit min node:
+                if (simplexBounds.min[node.axis] <= node.min + shape.center[node.axis])
+                    BIHTraverse(colliderIndex, simplexIndex, simplexStart, simplexSize,
+                                positions, orientations, radii, simplices, in simplexBounds,
+                                node.firstChild, contacts, optimizationIterations, optimizationTolerance);
+
+                // visit max node:
+                if (simplexBounds.max[node.axis] >= node.max + shape.center[node.axis])
+                    BIHTraverse(colliderIndex, simplexIndex, simplexStart, simplexSize,
+                                positions, orientations, radii, simplices, in simplexBounds,
+                                node.firstChild + 1, contacts, optimizationIterations, optimizationTolerance);
+            }
+            else
+            {
+                // check for contact against all triangles:
+                for (dataOffset = node.start; dataOffset < node.start + node.count; ++dataOffset)
+                {
+                    Edge t = edges[header.firstEdge + dataOffset];
+                    float4 v1 = new float4(vertices[header.firstVertex + t.i1], 0) + shape.center;
+                    float4 v2 = new float4(vertices[header.firstVertex + t.i2], 0) + shape.center;
+                    BurstAabb edgeBounds = new BurstAabb(v1, v2, shape.contactOffset + 0.01f);
+
+                    if (edgeBounds.IntersectsAabb(simplexBounds, shape.is2D != 0))
+                    {
+                        var co = new BurstContact() { bodyA = simplexIndex, bodyB = colliderIndex };
+                        float4 simplexBary = BurstMath.BarycenterForSimplexOfSize(simplexSize);
+
+                        var colliderPoint = BurstLocalOptimization.Optimize<BurstEdgeMesh>(ref this, positions, orientations, radii, simplices, simplexStart, simplexSize,
+                                                                            ref simplexBary, out float4 convexPoint, optimizationIterations, optimizationTolerance);
+
+                        co.pointB = colliderPoint.point;
+                        co.normal = colliderPoint.normal;
+                        co.pointA = simplexBary;
+
+                        contacts.Enqueue(co);
+                    }
+                }
+            }
+        }
+
+    }
+
+}
+#endif

Assets/Obi/Scripts/Common/Backends/Burst/Collisions/BurstEdgeMesh.cs.meta

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Assets/Obi/Scripts/Common/Backends/Burst/Collisions/BurstHeightField.cs

@@ -0,0 +1,184 @@
+#if (OBI_BURST && OBI_MATHEMATICS && OBI_COLLECTIONS)
+using Unity.Collections;
+using Unity.Mathematics;
+
+namespace Obi
+{
+    public struct BurstHeightField : BurstLocalOptimization.IDistanceFunction, IBurstCollider
+    {
+
+        public BurstColliderShape shape;
+        public BurstAffineTransform colliderToSolver;
+        public BurstAffineTransform solverToWorld;
+        public float dt;
+        public float collisionMargin;
+
+        public BurstMath.CachedTri tri;
+        public float4 triNormal;
+
+        public HeightFieldHeader header;
+        public NativeArray<float> heightFieldSamples;
+
+        public void Evaluate(float4 point, float4 radii, quaternion orientation, ref BurstLocalOptimization.SurfacePoint projectedPoint)
+        {
+            point = colliderToSolver.InverseTransformPoint(point);
+
+            float4 nearestPoint = BurstMath.NearestPointOnTri(tri, point, out float4 bary);
+            float4 normal = math.normalizesafe(point - nearestPoint);
+
+            // flip the contact normal if it points below ground: (doesn't work with holes)
+            //BurstMath.OneSidedNormal(triNormal, ref normal);
+
+            projectedPoint.point = colliderToSolver.TransformPoint(nearestPoint + normal * shape.contactOffset);
+            projectedPoint.normal = colliderToSolver.TransformDirection(normal);
+        }
+
+        public void Contacts(int colliderIndex,
+                             int rigidbodyIndex,
+                              NativeArray<BurstRigidbody> rigidbodies,
+
+                              NativeArray<float4> positions,
+                              NativeArray<quaternion> orientations,
+                              NativeArray<float4> velocities,
+                              NativeArray<float4> radii,
+
+                              NativeArray<int> simplices,
+                              in BurstAabb simplexBounds,
+                              int simplexIndex,
+                              int simplexStart,
+                              int simplexSize,
+
+                              NativeQueue<BurstContact>.ParallelWriter contacts,
+                              int optimizationIterations,
+                              float optimizationTolerance)
+        {
+            if (shape.dataIndex < 0) return;
+
+            triNormal = float4.zero;
+
+            var co = new BurstContact() { bodyA = simplexIndex, bodyB = colliderIndex };
+
+            int resolutionU = (int)shape.center.x;
+            int resolutionV = (int)shape.center.y;
+
+            // calculate terrain cell size:
+            float cellWidth = shape.size.x / (resolutionU - 1);
+            float cellHeight = shape.size.z / (resolutionV - 1);
+
+            // calculate particle bounds min/max cells:
+            int2 min = new int2((int)math.floor(simplexBounds.min[0] / cellWidth), (int)math.floor(simplexBounds.min[2] / cellHeight));
+            int2 max = new int2((int)math.floor(simplexBounds.max[0] / cellWidth), (int)math.floor(simplexBounds.max[2] / cellHeight));
+
+            for (int su = min[0]; su <= max[0]; ++su)
+            {
+                if (su >= 0 && su < resolutionU - 1)
+                {
+                    for (int sv = min[1]; sv <= max[1]; ++sv)
+                    {
+                        if (sv >= 0 && sv < resolutionV - 1)
+                        {
+                            // calculate neighbor sample indices:
+                            int csu1 = math.clamp(su + 1, 0, resolutionU - 1);
+                            int csv1 = math.clamp(sv + 1, 0, resolutionV - 1);
+
+                            // sample heights:
+                            float h1 = heightFieldSamples[header.firstSample + sv * resolutionU + su] * shape.size.y;
+                            float h2 = heightFieldSamples[header.firstSample + sv * resolutionU + csu1] * shape.size.y;
+                            float h3 = heightFieldSamples[header.firstSample + csv1 * resolutionU + su] * shape.size.y;
+                            float h4 = heightFieldSamples[header.firstSample + csv1 * resolutionU + csu1] * shape.size.y;
+
+                            if (h1 < 0) continue;
+                            h1 = math.abs(h1);
+                            h2 = math.abs(h2);
+                            h3 = math.abs(h3);
+                            h4 = math.abs(h4);
+
+                            float min_x = su * shape.size.x / (resolutionU - 1);
+                            float max_x = csu1 * shape.size.x / (resolutionU - 1);
+                            float min_z = sv * shape.size.z / (resolutionV - 1);
+                            float max_z = csv1 * shape.size.z / (resolutionV - 1);
+
+                            float4 convexPoint;
+                            float4 simplexBary = BurstMath.BarycenterForSimplexOfSize(simplexSize);
+
+                            // ------contact against the first triangle------:
+                            float4 v1 = new float4(min_x, h3, max_z, 0);
+                            float4 v2 = new float4(max_x, h4, max_z, 0);
+                            float4 v3 = new float4(min_x, h1, min_z, 0);
+
+                            tri.Cache(v1, v2, v3);
+                            triNormal.xyz = math.normalizesafe(math.cross((v2 - v1).xyz, (v3 - v1).xyz));
+
+                            var colliderPoint = BurstLocalOptimization.Optimize<BurstHeightField>(ref this, positions, orientations, radii, simplices, simplexStart, simplexSize,
+                                                                                ref simplexBary, out convexPoint, optimizationIterations, optimizationTolerance);
+
+                            float4 velocity = float4.zero;
+                            float simplexRadius = 0;
+                            for (int j = 0; j < simplexSize; ++j)
+                            {
+                                int particleIndex = simplices[simplexStart + j];
+                                simplexRadius += radii[particleIndex].x * simplexBary[j];
+                                velocity += velocities[particleIndex] * simplexBary[j];
+                            }
+
+                            float4 rbVelocity = float4.zero;
+                            if (rigidbodyIndex >= 0)
+                                rbVelocity = BurstMath.GetRigidbodyVelocityAtPoint(rigidbodyIndex, colliderPoint.point, rigidbodies, solverToWorld);
+
+                            float dAB = math.dot(convexPoint - colliderPoint.point, colliderPoint.normal);
+                            float vel = math.dot(velocity - rbVelocity, colliderPoint.normal);
+
+                            if (vel * dt + dAB <= simplexRadius + shape.contactOffset + collisionMargin)
+                            {
+                                co.pointB = colliderPoint.point;
+                                co.normal = colliderPoint.normal;
+                                co.pointA = simplexBary;
+                                contacts.Enqueue(co);
+                            }
+
+                            // ------contact against the second triangle------:
+                            v1 = new float4(min_x, h1, min_z, 0);
+                            v2 = new float4(max_x, h4, max_z, 0);
+                            v3 = new float4(max_x, h2, min_z, 0);
+
+                            tri.Cache(v1, v2, v3);
+                            triNormal.xyz = math.normalizesafe(math.cross((v2 - v1).xyz, (v3 - v1).xyz));
+
+                            colliderPoint = BurstLocalOptimization.Optimize<BurstHeightField>(ref this, positions, orientations, radii, simplices, simplexStart, simplexSize,
+                                                                                ref simplexBary, out convexPoint, optimizationIterations, optimizationTolerance);
+
+                            velocity = float4.zero;
+                            simplexRadius = 0;
+                            for (int j = 0; j < simplexSize; ++j)
+                            {
+                                int particleIndex = simplices[simplexStart + j];
+                                simplexRadius += radii[particleIndex].x * simplexBary[j];
+                                velocity += velocities[particleIndex] * simplexBary[j];
+                            }
+
+                            rbVelocity = float4.zero;
+                            if (rigidbodyIndex >= 0)
+                                rbVelocity = BurstMath.GetRigidbodyVelocityAtPoint(rigidbodyIndex, colliderPoint.point, rigidbodies, solverToWorld);
+
+                            dAB = math.dot(convexPoint - colliderPoint.point, colliderPoint.normal);
+                            vel = math.dot(velocity - rbVelocity, colliderPoint.normal);
+
+                            if (vel * dt + dAB <= simplexRadius + shape.contactOffset + collisionMargin)
+                            {
+                                co.pointB = colliderPoint.point;
+                                co.normal = colliderPoint.normal;
+                                co.pointA = simplexBary;
+
+                                contacts.Enqueue(co);
+                            }
+                        }
+                    }
+                }
+            }
+            
+        }
+
+    }
+
+}
+#endif

Assets/Obi/Scripts/Common/Backends/Burst/Collisions/BurstHeightField.cs.meta

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Assets/Obi/Scripts/Common/Backends/Burst/Collisions/BurstLocalOptimization.cs

@@ -0,0 +1,203 @@
+#if (OBI_BURST && OBI_MATHEMATICS && OBI_COLLECTIONS)
+using System;
+using System.Collections.Generic;
+using UnityEngine;
+using Unity.Collections;
+using Unity.Jobs;
+using Unity.Mathematics;
+using Unity.Burst;
+using System.Runtime.CompilerServices;
+
+namespace Obi
+{ 
+    public static class BurstLocalOptimization
+    {
+
+        /**
+         * point in the surface of a signed distance field.
+         */
+        public struct SurfacePoint
+        {
+            public float4 bary;
+            public float4 point;
+            public float4 normal;
+        }
+
+        public interface IDistanceFunction
+        {
+            void Evaluate(float4 point, float4 radii, quaternion orientation, ref SurfacePoint projectedPoint);
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        private static void GetInterpolatedSimplexData(int simplexStart,
+                                            int simplexSize,
+                                            NativeArray<int> simplices,
+                                            NativeArray<float4> positions,
+                                            NativeArray<quaternion> orientations,
+                                            NativeArray<float4> radii,
+                                            float4 convexBary,
+                                            out float4 convexPoint,
+                                            out float4 convexRadii,
+                                            out quaternion convexOrientation)
+        {
+            convexPoint = float4.zero;
+            convexRadii = float4.zero;
+            convexOrientation = new quaternion(0, 0, 0, 0);
+            for (int j = 0; j < simplexSize; ++j)
+            {
+                int particle = simplices[simplexStart + j];
+                convexPoint += positions[particle] * convexBary[j];
+                convexRadii += radii[particle] * convexBary[j];
+                convexOrientation.value += orientations[particle].value * convexBary[j];
+            }
+        }
+
+        public static SurfacePoint Optimize<T>(ref T function,
+                                               NativeArray<float4> positions,
+                                               NativeArray<quaternion> orientations,
+                                               NativeArray<float4> radii,
+                                               NativeArray<int> simplices,
+                                               int simplexStart,
+                                               int simplexSize,
+                                               ref float4 convexBary,
+                                               out float4 convexPoint,
+                                               int maxIterations = 16,
+                                               float tolerance = 0.004f) where T : struct, IDistanceFunction
+        {
+            var pointInFunction = new SurfacePoint();
+
+            // get cartesian coordinates of the initial guess:
+            GetInterpolatedSimplexData(simplexStart, simplexSize, simplices, positions, orientations, radii, convexBary, out convexPoint, out float4 convexThickness, out quaternion convexOrientation);
+
+            // for a 0-simplex (point), perform a single evaluation:
+            if (simplexSize == 1 || maxIterations < 1)
+                function.Evaluate(convexPoint, convexThickness, convexOrientation, ref pointInFunction);
+
+            // for a 1-simplex (edge), perform golden ratio search:
+            else if (simplexSize == 2)
+                GoldenSearch(ref function, simplexStart, simplexSize, positions, orientations, radii, simplices, ref convexPoint, ref convexThickness, ref convexOrientation, ref convexBary, ref pointInFunction, maxIterations, tolerance * 10);
+
+            // for higher-order simplices, use general Frank-Wolfe convex optimization:
+            else
+                FrankWolfe(ref function, simplexStart, simplexSize, positions, orientations, radii, simplices, ref convexPoint, ref convexThickness, ref convexOrientation, ref convexBary, ref pointInFunction, maxIterations, tolerance);
+            
+            return pointInFunction;
+        }
+
+        // Frank-Wolfe convex optimization algorithm. Returns closest point to a simplex in a signed distance function.
+        private static void FrankWolfe<T>(ref T function,
+                                          int simplexStart,
+                                          int simplexSize,
+                                          NativeArray<float4> positions,
+                                          NativeArray<quaternion> orientations,
+                                          NativeArray<float4> radii,
+                                          NativeArray<int> simplices,
+                                          ref float4 convexPoint,
+                                          ref float4 convexThickness,
+                                          ref quaternion convexOrientation,
+                                          ref float4 convexBary,
+                                          ref SurfacePoint pointInFunction,
+                                          int maxIterations,
+                                          float tolerance) where T : struct, IDistanceFunction
+        {
+            for (int i = 0; i < maxIterations; ++i)
+            {
+                // sample target function:
+                function.Evaluate(convexPoint, convexThickness, convexOrientation, ref pointInFunction);
+
+                // find descent direction:
+                int descent = 0;
+                float gap = float.MinValue;
+                for (int j = 0; j < simplexSize; ++j)
+                {
+                    int particle = simplices[simplexStart + j];
+                    float4 candidate = positions[particle] - convexPoint;
+
+                    // here, we adjust the candidate by projecting it to the engrosed simplex's surface:
+                    candidate -= pointInFunction.normal * (radii[particle].x - convexThickness.x);
+
+                    float corr = math.dot(-pointInFunction.normal, candidate);
+                    if (corr > gap)
+                    {
+                        descent = j;
+                        gap = corr;
+                    }
+                }
+
+                // if the duality gap is below tolerance threshold, stop iterating.
+                if (gap < tolerance)
+                    break;
+
+                // update the barycentric coords using 2/(i+2) as  the step factor
+                float step = 0.3f * 2.0f / (i + 2);
+                convexBary *= 1 - step;
+                convexBary[descent] += step;
+
+                // get cartesian coordinates of current solution:
+                GetInterpolatedSimplexData(simplexStart, simplexSize, simplices, positions, orientations, radii, convexBary, out convexPoint, out convexThickness, out convexOrientation);
+            }   
+        }
+
+        private static void GoldenSearch<T>(ref T function,
+                                            int simplexStart,
+                                            int simplexSize,
+                                            NativeArray<float4> positions,
+                                            NativeArray<quaternion> orientations,
+                                            NativeArray<float4> radii,
+                                            NativeArray<int> simplices,
+                                            ref float4 convexPoint,
+                                            ref float4 convexThickness,
+                                            ref quaternion convexOrientation,
+                                            ref float4 convexBary,
+                                            ref SurfacePoint pointInFunction,
+                                            int maxIterations,
+                                            float tolerance) where T : struct, IDistanceFunction
+        {
+            var pointInFunctionD = new SurfacePoint();
+            float4 convexPointD, convexThicknessD;
+            quaternion convexOrientationD;
+
+            float gr = (math.sqrt(5.0f) + 1) / 2.0f;
+            float u = 0, v = 1;
+            float c = v - (v - u) / gr;
+            float d = u + (v - u) / gr;
+
+            for (int i = 0; i < maxIterations; ++i)
+            {
+                // if the gap is below tolerance threshold, stop iterating.
+                if (math.abs(v - u) < tolerance * (math.abs(c) + math.abs(d)))
+                    break;
+
+                GetInterpolatedSimplexData(simplexStart, simplexSize, simplices, positions, orientations, radii, new float4(c, 1 - c, 0, 0), out convexPoint, out convexThickness, out convexOrientation);
+                GetInterpolatedSimplexData(simplexStart, simplexSize, simplices, positions, orientations, radii, new float4(d, 1 - d, 0, 0), out convexPointD, out convexThicknessD, out convexOrientationD);
+
+                function.Evaluate(convexPoint, convexThickness, convexOrientation, ref pointInFunction);
+                function.Evaluate(convexPointD, convexThicknessD, convexOrientationD, ref pointInFunctionD);
+
+                float4 candidateC = positions[simplices[simplexStart]] - pointInFunction.point;
+                float4 candidateD = positions[simplices[simplexStart + 1]] - pointInFunctionD.point;
+
+                candidateC -= pointInFunction.normal * (radii[simplices[simplexStart]].x - convexThickness.x);
+                candidateD -= pointInFunctionD.normal * (radii[simplices[simplexStart + 1]].x - convexThicknessD.x);
+
+                if (math.dot(-pointInFunction.normal, candidateC) < math.dot(-pointInFunctionD.normal, candidateD))
+                    v = d;
+                else
+                    u = c;
+
+                c = v - (v - u) / gr;
+                d = u + (v - u) / gr;
+            }
+
+            float mid = (v + u) * 0.5f;
+            convexBary.x = mid;
+            convexBary.y = (1 - mid);
+            GetInterpolatedSimplexData(simplexStart, simplexSize, simplices, positions, orientations, radii, convexBary, out convexPoint, out convexThickness, out convexOrientation);
+            function.Evaluate(convexPoint, convexThickness, convexOrientation, ref pointInFunction);
+        }
+
+
+    }
+
+}
+#endif

Assets/Obi/Scripts/Common/Backends/Burst/Collisions/BurstLocalOptimization.cs.meta

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Assets/Obi/Scripts/Common/Backends/Burst/Collisions/BurstSimplex.cs

@@ -0,0 +1,64 @@
+#if (OBI_BURST && OBI_MATHEMATICS && OBI_COLLECTIONS)
+using System;
+using System.Collections.Generic;
+using UnityEngine;
+using Unity.Collections;
+using Unity.Jobs;
+using Unity.Mathematics;
+using Unity.Burst;
+
+namespace Obi
+{
+    public struct BurstSimplex : BurstLocalOptimization.IDistanceFunction
+    {
+        public NativeArray<float4> positions;
+        public NativeArray<float4> radii;
+        public NativeArray<int> simplices;
+
+        public int simplexStart;
+        public int simplexSize;
+
+        private BurstMath.CachedTri tri;
+
+        public void CacheData()
+        {
+            if (simplexSize == 3)
+            {
+                tri.Cache(positions[simplices[simplexStart]],
+                          positions[simplices[simplexStart + 1]],
+                          positions[simplices[simplexStart + 2]]);
+            }
+        }
+
+        public void Evaluate(float4 point, float4 radii, quaternion orientation, ref BurstLocalOptimization.SurfacePoint projectedPoint)
+        {
+            switch (simplexSize)
+            {
+                case 1:
+                    {
+                        float4 p1 = positions[simplices[simplexStart]];
+                        projectedPoint.bary = new float4(1, 0, 0, 0);
+                        projectedPoint.point = p1;
+                    }
+                    break;
+                case 2:
+                    {
+                        float4 p1 = positions[simplices[simplexStart]];
+                        float4 p2 = positions[simplices[simplexStart + 1]];
+                        BurstMath.NearestPointOnEdge(p1, p2, point, out float mu);
+                        projectedPoint.bary = new float4(1 - mu, mu, 0, 0);
+                        projectedPoint.point = p1 * projectedPoint.bary[0] + p2 * projectedPoint.bary[1];
+            
+                    }break;
+                case 3:
+                        projectedPoint.point = BurstMath.NearestPointOnTri(tri, point, out projectedPoint.bary);
+                    break;
+            }
+
+            projectedPoint.normal = math.normalizesafe(point - projectedPoint.point);
+        }
+
+    }
+
+}
+#endif

Assets/Obi/Scripts/Common/Backends/Burst/Collisions/BurstSimplex.cs.meta

@@ -0,0 +1,11 @@
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Assets/Obi/Scripts/Common/Backends/Burst/Collisions/BurstSphere.cs

@@ -0,0 +1,64 @@
+#if (OBI_BURST && OBI_MATHEMATICS && OBI_COLLECTIONS)
+using Unity.Collections;
+using Unity.Mathematics;
+
+namespace Obi
+{
+    public struct BurstSphere : BurstLocalOptimization.IDistanceFunction, IBurstCollider
+    {
+        public BurstColliderShape shape;
+        public BurstAffineTransform colliderToSolver;
+        public float dt;
+
+        public void Evaluate(float4 point, float4 radii, quaternion orientation, ref BurstLocalOptimization.SurfacePoint projectedPoint)
+        {
+            float4 center = shape.center * colliderToSolver.scale;
+            point = colliderToSolver.InverseTransformPointUnscaled(point) - center;
+
+            if (shape.is2D != 0)
+                point[2] = 0;
+
+            float radius = shape.size.x * math.cmax(colliderToSolver.scale.xyz);
+            float distanceToCenter = math.length(point);
+
+            float4 normal = point / (distanceToCenter + BurstMath.epsilon);
+
+            projectedPoint.point = colliderToSolver.TransformPointUnscaled(center + normal * (radius + shape.contactOffset));
+            projectedPoint.normal = colliderToSolver.TransformDirection(normal);
+        }
+
+        public void Contacts(int colliderIndex,
+                             int rigidbodyIndex,
+                             NativeArray<BurstRigidbody> rigidbodies,
+
+                             NativeArray<float4> positions,
+                             NativeArray<quaternion> orientations,
+                             NativeArray<float4> velocities,
+                             NativeArray<float4> radii,
+
+                             NativeArray<int> simplices,
+                             in BurstAabb simplexBounds,
+                             int simplexIndex,
+                             int simplexStart,
+                             int simplexSize,
+
+                             NativeQueue<BurstContact>.ParallelWriter contacts,
+                             int optimizationIterations,
+                             float optimizationTolerance)
+        {
+            var co = new BurstContact() { bodyA = simplexIndex, bodyB = colliderIndex };
+            float4 simplexBary = BurstMath.BarycenterForSimplexOfSize(simplexSize);
+
+            var colliderPoint = BurstLocalOptimization.Optimize<BurstSphere>(ref this, positions, orientations, radii, simplices, simplexStart, simplexSize,
+                                                                             ref simplexBary, out float4 convexPoint, optimizationIterations, optimizationTolerance);
+
+            co.pointB = colliderPoint.point;
+            co.normal = colliderPoint.normal;
+            co.pointA = simplexBary;
+
+            contacts.Enqueue(co);
+        }
+    }
+
+}
+#endif

Assets/Obi/Scripts/Common/Backends/Burst/Collisions/BurstSphere.cs.meta

@@ -0,0 +1,11 @@
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Assets/Obi/Scripts/Common/Backends/Burst/Collisions/BurstTriangleMesh.cs

@@ -0,0 +1,149 @@
+#if (OBI_BURST && OBI_MATHEMATICS && OBI_COLLECTIONS)
+using Unity.Collections;
+using Unity.Mathematics;
+
+namespace Obi
+{
+    public struct BurstTriangleMesh : BurstLocalOptimization.IDistanceFunction, IBurstCollider
+    {
+        public BurstColliderShape shape;
+        public BurstAffineTransform colliderToSolver;
+        public BurstAffineTransform solverToWorld;
+
+        public TriangleMeshHeader header;
+        public NativeArray<BIHNode> bihNodes;
+        public NativeArray<Triangle> triangles;
+        public NativeArray<float3> vertices;
+
+        public float dt;
+        public float collisionMargin;
+
+        private BurstMath.CachedTri tri;
+
+        public void Evaluate(float4 point, float4 radii, quaternion orientation, ref BurstLocalOptimization.SurfacePoint projectedPoint)
+        {
+            point = colliderToSolver.InverseTransformPointUnscaled(point);
+
+            if (shape.is2D != 0)
+                point[2] = 0;
+
+            float4 nearestPoint = BurstMath.NearestPointOnTri(tri, point, out float4 bary);
+            float4 normal = math.normalizesafe(point - nearestPoint);
+
+            projectedPoint.point = colliderToSolver.TransformPointUnscaled(nearestPoint + normal * shape.contactOffset);
+            projectedPoint.normal = colliderToSolver.TransformDirection(normal);
+        }
+
+        public void Contacts(int colliderIndex,
+                             int rigidbodyIndex,
+                             NativeArray<BurstRigidbody> rigidbodies,
+
+                              NativeArray<float4> positions,
+                              NativeArray<quaternion> orientations,
+                              NativeArray<float4> velocities,
+                              NativeArray<float4> radii,
+
+                              NativeArray<int> simplices,
+                              in BurstAabb simplexBounds,
+                              int simplexIndex,
+                              int simplexStart,
+                              int simplexSize,
+
+                              NativeQueue<BurstContact>.ParallelWriter contacts,
+                              int optimizationIterations,
+                              float optimizationTolerance)
+        {
+
+            BIHTraverse(colliderIndex, rigidbodyIndex, simplexIndex, simplexStart, simplexSize,
+                        rigidbodies, positions, orientations, velocities, radii, simplices, in simplexBounds, 0, contacts, optimizationIterations, optimizationTolerance);
+            
+        }
+
+        private void BIHTraverse(int colliderIndex,
+                                 int rigidbodyIndex,
+                                 int simplexIndex,
+                                 int simplexStart,
+                                 int simplexSize,
+                                 NativeArray<BurstRigidbody> rigidbodies,
+                                 NativeArray<float4> positions,
+                                 NativeArray<quaternion> orientations,
+                                 NativeArray<float4> velocities,
+                                 NativeArray<float4> radii,
+                                 NativeArray<int> simplices,
+                                 in BurstAabb simplexBounds,
+                                 int nodeIndex,
+                                 NativeQueue<BurstContact>.ParallelWriter contacts,
+                                 int optimizationIterations,
+                                 float optimizationTolerance)
+        {
+            var node = bihNodes[header.firstNode + nodeIndex];
+
+            if (node.firstChild >= 0)
+            { 
+                // visit min node:
+                if (simplexBounds.min[node.axis] <= node.min)
+                    BIHTraverse(colliderIndex, rigidbodyIndex, simplexIndex, simplexStart, simplexSize,
+                                rigidbodies, positions, orientations, velocities, radii, simplices, in simplexBounds,
+                                node.firstChild, contacts, optimizationIterations, optimizationTolerance);
+
+                // visit max node:
+                if (simplexBounds.max[node.axis] >= node.max)
+                    BIHTraverse(colliderIndex, rigidbodyIndex, simplexIndex, simplexStart, simplexSize,
+                                rigidbodies, positions, orientations, velocities, radii, simplices, in simplexBounds,
+                                node.firstChild + 1, contacts, optimizationIterations, optimizationTolerance);
+            }
+            else
+            {
+                // check for contact against all triangles:
+                for (int dataOffset = node.start; dataOffset < node.start + node.count; ++dataOffset)
+                {
+                    Triangle t = triangles[header.firstTriangle + dataOffset];
+                    float4 v1 = new float4(vertices[header.firstVertex + t.i1], 0);
+                    float4 v2 = new float4(vertices[header.firstVertex + t.i2], 0);
+                    float4 v3 = new float4(vertices[header.firstVertex + t.i3], 0);
+                    BurstAabb triangleBounds = new BurstAabb(v1, v2, v3, shape.contactOffset + collisionMargin);
+
+                    if (triangleBounds.IntersectsAabb(simplexBounds, shape.is2D != 0))
+                    {
+                        float4 simplexBary = BurstMath.BarycenterForSimplexOfSize(simplexSize);
+                        tri.Cache(v1 * colliderToSolver.scale, v2 * colliderToSolver.scale, v3 * colliderToSolver.scale);
+
+                        var colliderPoint = BurstLocalOptimization.Optimize<BurstTriangleMesh>(ref this, positions, orientations, radii, simplices, simplexStart, simplexSize,
+                                                                            ref simplexBary, out float4 simplexPoint, optimizationIterations, optimizationTolerance);
+
+                        float4 velocity = float4.zero;
+                        float simplexRadius = 0;
+                        for (int j = 0; j < simplexSize; ++j)
+                        {
+                            int particleIndex = simplices[simplexStart + j];
+                            simplexRadius += radii[particleIndex].x * simplexBary[j];
+                            velocity += velocities[particleIndex] * simplexBary[j];
+                        }
+
+                        float4 rbVelocity = float4.zero;
+                        if (rigidbodyIndex >= 0)
+                            rbVelocity = BurstMath.GetRigidbodyVelocityAtPoint(rigidbodyIndex, colliderPoint.point, rigidbodies, solverToWorld);
+
+                        float dAB = math.dot(simplexPoint - colliderPoint.point, colliderPoint.normal);
+                        float vel = math.dot(velocity     - rbVelocity, colliderPoint.normal); 
+
+                        if (vel * dt + dAB <= simplexRadius + shape.contactOffset + collisionMargin)
+                        {
+                            contacts.Enqueue(new BurstContact()
+                            {
+                                bodyA = simplexIndex,
+                                bodyB = colliderIndex,
+                                pointA = simplexBary,
+                                pointB = colliderPoint.point,
+                                normal = colliderPoint.normal,
+                            });
+                        }
+                    }
+                }
+            }
+        }
+
+    }
+
+}
+#endif

Assets/Obi/Scripts/Common/Backends/Burst/Collisions/BurstTriangleMesh.cs.meta

@@ -0,0 +1,11 @@
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Assets/Obi/Scripts/Common/Backends/Burst/Collisions/IBurstCollider.cs

@@ -0,0 +1,29 @@
+#if (OBI_BURST && OBI_MATHEMATICS && OBI_COLLECTIONS)
+using Unity.Collections;
+using Unity.Mathematics;
+
+namespace Obi
+{
+    interface IBurstCollider
+    {
+        void Contacts(int colliderIndex,
+                      int rigidbodyIndex,
+                      NativeArray<BurstRigidbody> rigidbodies,
+
+                      NativeArray<float4> positions,
+                      NativeArray<quaternion> orientations,
+                      NativeArray<float4> velocities,
+                      NativeArray<float4> radii,
+
+                      NativeArray<int> simplices,
+                      in BurstAabb simplexBounds,
+                      int simplexIndex,
+                      int simplexStart,
+                      int simplexSize,
+
+                      NativeQueue<BurstContact>.ParallelWriter contacts,
+                      int optimizationIterations,
+                      float optimizationTolerance);
+    }
+}
+#endif

Assets/Obi/Scripts/Common/Backends/Burst/Collisions/IBurstCollider.cs.meta

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Assets/Obi/Scripts/Common/Backends/Burst/Constraints.meta

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Assets/Obi/Scripts/Common/Backends/Burst/Constraints/Aerodynamics.meta

@@ -0,0 +1,8 @@
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Assets/Obi/Scripts/Common/Backends/Burst/Constraints/Aerodynamics/BurstAerodynamicConstraints.cs

@@ -0,0 +1,26 @@
+#if (OBI_BURST && OBI_MATHEMATICS && OBI_COLLECTIONS)
+using System;
+
+namespace Obi
+{
+    public class BurstAerodynamicConstraints : BurstConstraintsImpl<BurstAerodynamicConstraintsBatch>
+    {
+        public BurstAerodynamicConstraints(BurstSolverImpl solver) : base(solver, Oni.ConstraintType.Aerodynamics)
+        {
+        }
+
+        public override IConstraintsBatchImpl CreateConstraintsBatch()
+        {
+            var dataBatch = new BurstAerodynamicConstraintsBatch(this);
+            batches.Add(dataBatch);
+            return dataBatch;
+        }
+
+        public override void RemoveBatch(IConstraintsBatchImpl batch)
+        {
+            batches.Remove(batch as BurstAerodynamicConstraintsBatch);
+            batch.Destroy();
+        }
+    }
+}
+#endif

Assets/Obi/Scripts/Common/Backends/Burst/Constraints/Aerodynamics/BurstAerodynamicConstraints.cs.meta

@@ -0,0 +1,11 @@
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Assets/Obi/Scripts/Common/Backends/Burst/Constraints/Aerodynamics/BurstAerodynamicConstraintsBatch.cs

@@ -0,0 +1,112 @@
+#if (OBI_BURST && OBI_MATHEMATICS && OBI_COLLECTIONS)
+using UnityEngine;
+using Unity.Jobs;
+using Unity.Collections;
+using Unity.Collections.LowLevel.Unsafe;
+using Unity.Mathematics;
+using Unity.Burst;
+using System.Collections;
+
+namespace Obi
+{
+    public class BurstAerodynamicConstraintsBatch : BurstConstraintsBatchImpl, IAerodynamicConstraintsBatchImpl
+    {
+        private NativeArray<float> aerodynamicCoeffs;
+
+        public BurstAerodynamicConstraintsBatch(BurstAerodynamicConstraints constraints)
+        {
+            m_Constraints = constraints;
+            m_ConstraintType = Oni.ConstraintType.Aerodynamics;
+        }
+
+        public void SetAerodynamicConstraints(ObiNativeIntList particleIndices, ObiNativeFloatList aerodynamicCoeffs, int count)
+        {
+            this.particleIndices = particleIndices.AsNativeArray<int>();
+            this.aerodynamicCoeffs = aerodynamicCoeffs.AsNativeArray<float>();
+            m_ConstraintCount = count;
+        }
+
+        public override JobHandle Initialize(JobHandle inputDeps, float substepTime)
+        {
+            return inputDeps;
+        }
+
+        public override JobHandle Evaluate(JobHandle inputDeps, float stepTime, float substepTime, int substeps)
+        {
+            var projectConstraints = new AerodynamicConstraintsBatchJob()
+            {
+                particleIndices = particleIndices,
+                aerodynamicCoeffs = aerodynamicCoeffs,
+                positions = solverImplementation.positions,
+                velocities = solverImplementation.velocities,
+                normals = solverImplementation.normals,
+                wind = solverImplementation.wind,
+                invMasses = solverImplementation.invMasses,
+                deltaTime = substepTime
+            };
+
+            return projectConstraints.Schedule(m_ConstraintCount, 32, inputDeps);
+        }
+
+        public override JobHandle Apply(JobHandle inputDeps, float substepTime)
+        {
+            return inputDeps;
+        }
+
+        [BurstCompile]
+        public struct AerodynamicConstraintsBatchJob : IJobParallelFor
+        {
+            [ReadOnly] public NativeArray<int> particleIndices;
+            [ReadOnly] [NativeDisableParallelForRestriction] public NativeArray<float> aerodynamicCoeffs;
+
+            [ReadOnly] public NativeArray<float4> positions; 
+            [ReadOnly] public NativeArray<float4> normals;
+            [ReadOnly] public NativeArray<float4> wind;
+            [ReadOnly] public NativeArray<float> invMasses;
+
+            [NativeDisableContainerSafetyRestriction]
+            public NativeArray<float4> velocities;
+
+            [ReadOnly] public float deltaTime;
+
+            public void Execute(int i)
+            {
+                int p = particleIndices[i];
+
+                float area = aerodynamicCoeffs[i * 3];
+                float dragCoeff = aerodynamicCoeffs[i * 3 + 1];
+                float liftCoeff = aerodynamicCoeffs[i * 3 + 2];
+
+                if (invMasses[p] > 0)
+                {
+                    float4 relVelocity = velocities[p] - wind[p];
+                    float rvSqrMag = math.lengthsq(relVelocity);
+
+                    if (rvSqrMag < BurstMath.epsilon)
+                        return;
+
+                    float4 rvNorm = relVelocity / math.sqrt(rvSqrMag);
+
+                    // calculate surface normal (always facing wind)
+                    float4 surfNormal = normals[p] * math.sign(math.dot(normals[p], rvNorm));
+
+                    // aerodynamic_factor was originally multiplied by air_density. The density is now premultiplied in lift and drag.
+                    float aerodynamicFactor = 0.5f * rvSqrMag * area;
+                    float attackAngle = math.dot(surfNormal,rvNorm);
+
+                    float3 liftDirection = math.normalizesafe(math.cross(math.cross(surfNormal.xyz, rvNorm.xyz), rvNorm.xyz));
+
+                    //drag:
+                    velocities[p] += (-dragCoeff * rvNorm +
+
+                                      // lift:
+                                      liftCoeff * new float4(liftDirection.xyz,0)) *
+
+                                      // scale
+                                      attackAngle * math.min(aerodynamicFactor * invMasses[p] * deltaTime, 1000);
+                }
+            }
+        }
+    }
+}
+#endif

Assets/Obi/Scripts/Common/Backends/Burst/Constraints/Aerodynamics/BurstAerodynamicConstraintsBatch.cs.meta

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Assets/Obi/Scripts/Common/Backends/Burst/Constraints/Bend.meta

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Assets/Obi/Scripts/Common/Backends/Burst/Constraints/Bend/BurstBendConstraints.cs

@@ -0,0 +1,26 @@
+#if (OBI_BURST && OBI_MATHEMATICS && OBI_COLLECTIONS)
+using System;
+
+namespace Obi
+{
+    public class BurstBendConstraints : BurstConstraintsImpl<BurstBendConstraintsBatch>
+    {
+        public BurstBendConstraints(BurstSolverImpl solver) : base(solver, Oni.ConstraintType.Bending)
+        {
+        }
+
+        public override IConstraintsBatchImpl CreateConstraintsBatch()
+        {
+            var dataBatch = new BurstBendConstraintsBatch(this);
+            batches.Add(dataBatch);
+            return dataBatch;
+        }
+
+        public override void RemoveBatch(IConstraintsBatchImpl batch)
+        {
+            batches.Remove(batch as BurstBendConstraintsBatch);
+            batch.Destroy();
+        }
+    }
+}
+#endif

Assets/Obi/Scripts/Common/Backends/Burst/Constraints/Bend/BurstBendConstraints.cs.meta

@@ -0,0 +1,11 @@
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Assets/Obi/Scripts/Common/Backends/Burst/Constraints/Bend/BurstBendConstraintsBatch.cs

@@ -0,0 +1,169 @@
+#if (OBI_BURST && OBI_MATHEMATICS && OBI_COLLECTIONS)
+using UnityEngine;
+using Unity.Jobs;
+using Unity.Collections;
+using Unity.Collections.LowLevel.Unsafe;
+using Unity.Mathematics;
+using Unity.Burst;
+using System.Collections;
+
+namespace Obi
+{
+    public class BurstBendConstraintsBatch : BurstConstraintsBatchImpl, IBendConstraintsBatchImpl
+    {
+        private NativeArray<float> restBends;
+        private NativeArray<float2> stiffnesses;
+        private NativeArray<float2> plasticity;
+
+        BendConstraintsBatchJob projectConstraints;
+        ApplyBendConstraintsBatchJob applyConstraints;
+
+        public BurstBendConstraintsBatch(BurstBendConstraints constraints)
+        {
+            m_Constraints = constraints;
+            m_ConstraintType = Oni.ConstraintType.Bending;
+        }
+
+        public void SetBendConstraints(ObiNativeIntList particleIndices, ObiNativeFloatList restBends, ObiNativeVector2List bendingStiffnesses, ObiNativeVector2List plasticity, ObiNativeFloatList lambdas, int count)
+        {
+            this.particleIndices = particleIndices.AsNativeArray<int>();
+            this.restBends = restBends.AsNativeArray<float>();
+            this.stiffnesses = bendingStiffnesses.AsNativeArray<float2>();
+            this.plasticity = plasticity.AsNativeArray<float2>();
+            this.lambdas = lambdas.AsNativeArray<float>();
+            m_ConstraintCount = count;
+
+            projectConstraints.particleIndices = this.particleIndices;
+            projectConstraints.restBends = this.restBends;
+            projectConstraints.stiffnesses = this.stiffnesses;
+            projectConstraints.plasticity = this.plasticity;
+            projectConstraints.lambdas = this.lambdas;
+
+            applyConstraints.particleIndices = this.particleIndices;
+        }
+
+        public override JobHandle Evaluate(JobHandle inputDeps, float stepTime, float substepTime, int substeps)
+        {
+            projectConstraints.positions = solverImplementation.positions;
+            projectConstraints.invMasses = solverImplementation.invMasses;
+            projectConstraints.deltas = solverImplementation.positionDeltas;
+            projectConstraints.counts = solverImplementation.positionConstraintCounts;
+            projectConstraints.deltaTime = substepTime;
+
+            return projectConstraints.Schedule(m_ConstraintCount, 32, inputDeps);
+        }
+
+        public override JobHandle Apply(JobHandle inputDeps, float substepTime)
+        {
+            var parameters = solverAbstraction.GetConstraintParameters(m_ConstraintType);
+
+            applyConstraints.positions = solverImplementation.positions;
+            applyConstraints.deltas = solverImplementation.positionDeltas;
+            applyConstraints.counts = solverImplementation.positionConstraintCounts;
+            applyConstraints.sorFactor = parameters.SORFactor;
+
+            return applyConstraints.Schedule(m_ConstraintCount, 64, inputDeps);
+        }
+
+        [BurstCompile]
+        public struct BendConstraintsBatchJob : IJobParallelFor
+        {
+            [ReadOnly] public NativeArray<int> particleIndices;
+            [ReadOnly] public NativeArray<float2> stiffnesses;
+            [ReadOnly] public NativeArray<float2> plasticity; //plastic yield, creep
+            public NativeArray<float> restBends;
+            public NativeArray<float> lambdas;
+
+            [ReadOnly] public NativeArray<float4> positions;
+            [ReadOnly] public NativeArray<float> invMasses;
+
+            [NativeDisableContainerSafetyRestriction][NativeDisableParallelForRestriction] public NativeArray<float4> deltas;
+            [NativeDisableContainerSafetyRestriction][NativeDisableParallelForRestriction] public NativeArray<int> counts;
+
+            [ReadOnly] public float deltaTime;
+
+            public void Execute(int i)
+            {
+                int p1 = particleIndices[i * 3];
+                int p2 = particleIndices[i * 3 + 1];
+                int p3 = particleIndices[i * 3 + 2];
+
+                float w1 = invMasses[p1];
+                float w2 = invMasses[p2];
+                float w3 = invMasses[p3];
+
+                float wsum = w1 + w2 + 2 * w3;
+
+                float4 bendVector = positions[p3] - (positions[p1] + positions[p2] + positions[p3]) / 3.0f;
+                float bend = math.length(bendVector);
+
+             
+                float constraint = bend - restBends[i];
+
+                constraint = math.max(0, constraint - stiffnesses[i].x) +
+                             math.min(0, constraint + stiffnesses[i].x);
+
+                // plasticity:
+                if (math.abs(constraint) > plasticity[i].x)  
+                    restBends[i] += constraint * plasticity[i].y * deltaTime;
+
+                // calculate time adjusted compliance
+                float compliance = stiffnesses[i].y / (deltaTime * deltaTime);
+
+                // since the third particle moves twice the amount of the other 2, the modulus of its gradient is 2:
+                float dlambda = (-constraint - compliance * lambdas[i]) / (wsum + compliance + BurstMath.epsilon);
+                float4 correction = dlambda * bendVector / (bend + BurstMath.epsilon);
+
+                lambdas[i] += dlambda;
+
+                deltas[p1] -= correction * 2 * w1;
+                deltas[p2] -= correction * 2 * w2;
+                deltas[p3] += correction * 4 * w3;
+
+                counts[p1]++;
+                counts[p2]++;
+                counts[p3]++;
+            }
+        }
+
+        [BurstCompile]
+        public struct ApplyBendConstraintsBatchJob : IJobParallelFor
+        {
+            [ReadOnly] public NativeArray<int> particleIndices;
+            [ReadOnly] public float sorFactor;
+
+            [NativeDisableContainerSafetyRestriction] [NativeDisableParallelForRestriction] public NativeArray<float4> positions;
+            [NativeDisableContainerSafetyRestriction] [NativeDisableParallelForRestriction] public NativeArray<float4> deltas;
+            [NativeDisableContainerSafetyRestriction] [NativeDisableParallelForRestriction] public NativeArray<int> counts;
+
+            public void Execute(int i)
+            {
+                int p1 = particleIndices[i * 3];
+                int p2 = particleIndices[i * 3 + 1];
+                int p3 = particleIndices[i * 3 + 2];
+
+                if (counts[p1] > 0)
+                {
+                    positions[p1] += deltas[p1] * sorFactor / counts[p1];
+                    deltas[p1] = float4.zero;
+                    counts[p1] = 0;
+                }
+
+                if (counts[p2] > 0)
+                {
+                    positions[p2] += deltas[p2] * sorFactor / counts[p2];
+                    deltas[p2] = float4.zero;
+                    counts[p2] = 0;
+                }
+
+                if (counts[p3] > 0)
+                {
+                    positions[p3] += deltas[p3] * sorFactor / counts[p3];
+                    deltas[p3] = float4.zero;
+                    counts[p3] = 0;
+                }
+            }
+        }
+    }
+}
+#endif

Assets/Obi/Scripts/Common/Backends/Burst/Constraints/Bend/BurstBendConstraintsBatch.cs.meta

@@ -0,0 +1,11 @@
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+guid: 3ca9c1fed63774363964743eb64fb68b
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+  serializedVersion: 2
+  defaultReferences: []
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+  userData: 
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Assets/Obi/Scripts/Common/Backends/Burst/Constraints/BendTwist.meta

@@ -0,0 +1,8 @@
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Assets/Obi/Scripts/Common/Backends/Burst/Constraints/BendTwist/BurstBendTwistConstraints.cs

@@ -0,0 +1,26 @@
+#if (OBI_BURST && OBI_MATHEMATICS && OBI_COLLECTIONS)
+using System;
+
+namespace Obi
+{
+    public class BurstBendTwistConstraints : BurstConstraintsImpl<BurstBendTwistConstraintsBatch>
+    {
+        public BurstBendTwistConstraints(BurstSolverImpl solver) : base(solver, Oni.ConstraintType.BendTwist)
+        {
+        }
+
+        public override IConstraintsBatchImpl CreateConstraintsBatch()
+        {
+            var dataBatch = new BurstBendTwistConstraintsBatch(this);
+            batches.Add(dataBatch);
+            return dataBatch;
+        }
+
+        public override void RemoveBatch(IConstraintsBatchImpl batch)
+        {
+            batches.Remove(batch as BurstBendTwistConstraintsBatch);
+            batch.Destroy();
+        }
+    }
+}
+#endif

Assets/Obi/Scripts/Common/Backends/Burst/Constraints/BendTwist/BurstBendTwistConstraints.cs.meta

@@ -0,0 +1,11 @@
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Assets/Obi/Scripts/Common/Backends/Burst/Constraints/BendTwist/BurstBendTwistConstraintsBatch.cs

@@ -0,0 +1,182 @@
+#if (OBI_BURST && OBI_MATHEMATICS && OBI_COLLECTIONS)
+using UnityEngine;
+using Unity.Jobs;
+using Unity.Collections;
+using Unity.Collections.LowLevel.Unsafe;
+using Unity.Mathematics;
+using Unity.Burst;
+using System.Collections;
+
+namespace Obi
+{
+    public class BurstBendTwistConstraintsBatch : BurstConstraintsBatchImpl, IBendTwistConstraintsBatchImpl
+    {
+        private NativeArray<int> orientationIndices;
+        private NativeArray<quaternion> restDarboux;
+        private NativeArray<float3> stiffnesses;
+        private NativeArray<float2> plasticity;
+
+        public BurstBendTwistConstraintsBatch(BurstBendTwistConstraints constraints)
+        {
+            m_Constraints = constraints;
+            m_ConstraintType = Oni.ConstraintType.BendTwist;
+        }
+
+        public void SetBendTwistConstraints(ObiNativeIntList orientationIndices, ObiNativeQuaternionList restDarboux, ObiNativeVector3List stiffnesses, ObiNativeVector2List plasticity, ObiNativeFloatList lambdas, int count)
+        {
+            this.orientationIndices = orientationIndices.AsNativeArray<int>();
+            this.restDarboux = restDarboux.AsNativeArray<quaternion>();
+            this.stiffnesses = stiffnesses.AsNativeArray<float3>();
+            this.plasticity = plasticity.AsNativeArray<float2>();
+            this.lambdas = lambdas.AsNativeArray<float>();
+            m_ConstraintCount = count;
+        }
+
+        public override JobHandle Evaluate(JobHandle inputDeps, float stepTime, float substepTime, int substeps)
+        {
+            var projectConstraints = new BendTwistConstraintsBatchJob()
+            {
+                orientationIndices = orientationIndices,
+                restDarboux = restDarboux,
+                stiffnesses = stiffnesses,
+                plasticity = plasticity,
+                lambdas = lambdas.Reinterpret<float, float3>(),
+
+                orientations = solverImplementation.orientations,
+                invRotationalMasses = solverImplementation.invRotationalMasses,
+
+                orientationDeltas = solverImplementation.orientationDeltas,
+                orientationCounts = solverImplementation.orientationConstraintCounts ,
+
+                deltaTime = substepTime
+            };
+
+            return projectConstraints.Schedule(m_ConstraintCount, 32, inputDeps);
+        }
+
+        public override JobHandle Apply(JobHandle inputDeps, float substepTime)
+        {
+            var parameters = solverAbstraction.GetConstraintParameters(m_ConstraintType);
+
+            var applyConstraints = new ApplyBendTwistConstraintsBatchJob()
+            {
+                orientationIndices = orientationIndices,
+
+                orientations = solverImplementation.orientations,
+                orientationDeltas = solverImplementation.orientationDeltas,
+                orientationCounts = solverImplementation.orientationConstraintCounts,
+
+                sorFactor = parameters.SORFactor
+            };
+
+            return applyConstraints.Schedule(m_ConstraintCount, 64, inputDeps);
+        }
+
+        [BurstCompile]
+        public struct BendTwistConstraintsBatchJob : IJobParallelFor
+        {
+            [ReadOnly] public NativeArray<int> orientationIndices;
+            [ReadOnly] public NativeArray<float3> stiffnesses;
+            [ReadOnly] public NativeArray<float2> plasticity;
+            public NativeArray<quaternion> restDarboux;
+            public NativeArray<float3> lambdas;
+
+            [ReadOnly] public NativeArray<quaternion> orientations;
+            [ReadOnly] public NativeArray<float> invRotationalMasses;
+
+            [NativeDisableContainerSafetyRestriction][NativeDisableParallelForRestriction] public NativeArray<quaternion> orientationDeltas;
+            [NativeDisableContainerSafetyRestriction][NativeDisableParallelForRestriction] public NativeArray<int> orientationCounts;
+
+            [ReadOnly] public float deltaTime;
+
+            public void Execute(int i)
+            {
+                int q1 = orientationIndices[i * 2];
+                int q2 = orientationIndices[i * 2 + 1];
+
+                float w1 = invRotationalMasses[q1];
+                float w2 = invRotationalMasses[q2];
+
+                // calculate time adjusted compliance
+                float3 compliances = stiffnesses[i] / (deltaTime * deltaTime);
+
+                // rest and current darboux vectors
+                quaternion rest = restDarboux[i];
+                quaternion omega = math.mul(math.conjugate(orientations[q1]), orientations[q2]);
+
+                quaternion omega_plus;
+                omega_plus.value = omega.value + rest.value;  //delta Omega with - omega_0
+                omega.value -= rest.value;                    //delta Omega with + omega_0
+
+                if (math.lengthsq(omega.value) > math.lengthsq(omega_plus.value))
+                    omega = omega_plus;
+
+                // plasticity
+                if (math.lengthsq(omega.value) > plasticity[i].x * plasticity[i].x)
+                {
+                    rest.value += omega.value * plasticity[i].y * deltaTime;
+                    restDarboux[i] = rest;
+                }
+
+                float3 dlambda = (omega.value.xyz - compliances * lambdas[i]) / (compliances + new float3(w1 + w2 + BurstMath.epsilon));
+
+                //discrete Darboux vector does not have vanishing scalar part
+                quaternion dlambdaQ = new quaternion(dlambda[0], dlambda[1], dlambda[2],0);
+
+                quaternion d1 = orientationDeltas[q1];
+                quaternion d2 = orientationDeltas[q2];
+
+                d1.value += math.mul(orientations[q2], dlambdaQ).value * w1;
+                d2.value -= math.mul(orientations[q1], dlambdaQ).value * w2;
+
+                orientationDeltas[q1] = d1;
+                orientationDeltas[q2] = d2;
+
+                orientationCounts[q1]++;
+                orientationCounts[q2]++;
+
+                lambdas[i] += dlambda;
+
+            }
+        }
+
+        [BurstCompile]
+        public struct ApplyBendTwistConstraintsBatchJob : IJobParallelFor
+        {
+            [ReadOnly] public NativeArray<int> orientationIndices;
+            [ReadOnly] public float sorFactor;
+
+            [NativeDisableContainerSafetyRestriction] [NativeDisableParallelForRestriction] public NativeArray<quaternion> orientations;
+            [NativeDisableContainerSafetyRestriction] [NativeDisableParallelForRestriction] public NativeArray<quaternion> orientationDeltas;
+            [NativeDisableContainerSafetyRestriction] [NativeDisableParallelForRestriction] public NativeArray<int> orientationCounts;
+
+            public void Execute(int i)
+            {
+                int p1 = orientationIndices[i * 2];
+                int p2 = orientationIndices[i * 2 + 1];
+
+                if (orientationCounts[p1] > 0)
+                {
+                    quaternion q = orientations[p1];
+                    q.value += orientationDeltas[p1].value * sorFactor / orientationCounts[p1];
+                    orientations[p1] = math.normalize(q);
+
+                    orientationDeltas[p1] = new quaternion(0, 0, 0, 0);
+                    orientationCounts[p1] = 0;
+                }
+
+                if (orientationCounts[p2] > 0)
+                {
+                    quaternion q = orientations[p2];
+                    q.value += orientationDeltas[p2].value * sorFactor / orientationCounts[p2];
+                    orientations[p2] = math.normalize(q);
+
+                    orientationDeltas[p2] = new quaternion(0, 0, 0, 0);
+                    orientationCounts[p2] = 0;
+                }
+            }
+
+        }
+    }
+}
+#endif

Assets/Obi/Scripts/Common/Backends/Burst/Constraints/BendTwist/BurstBendTwistConstraintsBatch.cs.meta

@@ -0,0 +1,11 @@
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+guid: c6235d2e315a94287ab8a219496d7961
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Assets/Obi/Scripts/Common/Backends/Burst/Constraints/BurstConstraintsBatchImpl.cs

@@ -0,0 +1,109 @@
+#if (OBI_BURST && OBI_MATHEMATICS && OBI_COLLECTIONS)
+using UnityEngine;
+using Unity.Burst;
+using Unity.Jobs;
+using Unity.Collections;
+using Unity.Collections.LowLevel.Unsafe;
+using Unity.Mathematics;
+using System.Collections;
+
+namespace Obi
+{
+    public abstract class BurstConstraintsBatchImpl : IConstraintsBatchImpl
+    {
+        protected IBurstConstraintsImpl m_Constraints;
+        protected Oni.ConstraintType m_ConstraintType;
+
+        protected bool m_Enabled = true;
+        protected int m_ConstraintCount = 0;
+
+        public Oni.ConstraintType constraintType
+        {
+            get { return m_ConstraintType; }
+        }
+
+        public bool enabled
+        {
+            set
+            {
+                if (m_Enabled != value)
+                    m_Enabled = value;
+            }
+            get { return m_Enabled; }
+        }
+
+        public IConstraints constraints
+        {
+            get { return m_Constraints; }
+        }
+
+        public ObiSolver solverAbstraction
+        {
+            get { return ((BurstSolverImpl)m_Constraints.solver).abstraction; }
+        }
+
+        public BurstSolverImpl solverImplementation
+        {
+            get { return (BurstSolverImpl)m_Constraints.solver; }
+        }
+
+        protected NativeArray<int> particleIndices;
+        protected NativeArray<float> lambdas;
+
+        public virtual JobHandle Initialize(JobHandle inputDeps, float substepTime)
+        {
+            if (lambdas.IsCreated)
+            {
+                // no need for jobs here, memclear is faster and we don't pay scheduling overhead.
+                unsafe
+                {
+                    UnsafeUtility.MemClear(NativeArrayUnsafeUtility.GetUnsafeBufferPointerWithoutChecks(lambdas),
+                                           lambdas.Length * UnsafeUtility.SizeOf<float>());
+                }
+            }
+            return inputDeps;
+        }
+
+        // implemented by concrete constraint subclasses.
+        public abstract JobHandle Evaluate(JobHandle inputDeps, float stepTime, float substepTime, int substeps);
+        public abstract JobHandle Apply(JobHandle inputDeps, float substepTime);
+
+        public virtual void Destroy()
+        {
+            // clean resources allocated by the batch, no need for a default implementation.
+        }
+
+        public void SetConstraintCount(int constraintCount)
+        {
+            m_ConstraintCount = constraintCount;
+        }
+        public int GetConstraintCount()
+        {
+            return m_ConstraintCount;
+        }
+
+        public static void ApplyPositionDelta(int particleIndex, float sorFactor, ref NativeArray<float4> positions, ref NativeArray<float4> deltas, ref NativeArray<int> counts)
+        {
+            if (counts[particleIndex] > 0)
+            {
+                positions[particleIndex] += deltas[particleIndex] * sorFactor / counts[particleIndex];
+                deltas[particleIndex] = float4.zero;
+                counts[particleIndex] = 0;
+            }
+        }
+
+        public static void ApplyOrientationDelta(int particleIndex, float sorFactor, ref NativeArray<quaternion> orientations, ref NativeArray<quaternion> deltas, ref NativeArray<int> counts)
+        {
+            if (counts[particleIndex] > 0)
+            {
+                quaternion q = orientations[particleIndex];
+                q.value += deltas[particleIndex].value * sorFactor / counts[particleIndex];
+                orientations[particleIndex] = math.normalize(q);
+
+                deltas[particleIndex] = new quaternion(0, 0, 0, 0);
+                counts[particleIndex] = 0;
+            }
+        }
+    }
+}
+#endif

Assets/Obi/Scripts/Common/Backends/Burst/Constraints/BurstConstraintsBatchImpl.cs.meta

@@ -0,0 +1,11 @@
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Assets/Obi/Scripts/Common/Backends/Burst/Constraints/BurstConstraintsImpl.cs

@@ -0,0 +1,145 @@
+#if (OBI_BURST && OBI_MATHEMATICS && OBI_COLLECTIONS)
+using UnityEngine;
+using Unity.Jobs;
+using Unity.Collections;
+using System.Collections;
+using System.Collections.Generic;
+
+namespace Obi
+{
+    public interface IBurstConstraintsImpl : IConstraints
+    {
+        JobHandle Initialize(JobHandle inputDeps, float substepTime);
+        JobHandle Project(JobHandle inputDeps, float stepTime, float substepTime, int substeps);
+        void Dispose();
+
+        IConstraintsBatchImpl CreateConstraintsBatch();
+        void RemoveBatch(IConstraintsBatchImpl batch);
+    }
+
+    public abstract class BurstConstraintsImpl<T> : IBurstConstraintsImpl where T : BurstConstraintsBatchImpl
+    {
+        protected BurstSolverImpl m_Solver;
+        public List<T> batches = new List<T>();
+
+        protected Oni.ConstraintType m_ConstraintType;
+
+        public Oni.ConstraintType constraintType
+        {
+            get { return m_ConstraintType; }
+        }
+
+        public ISolverImpl solver
+        {
+            get { return m_Solver; }
+        }
+
+        public BurstConstraintsImpl(BurstSolverImpl solver, Oni.ConstraintType constraintType)
+        {
+            this.m_ConstraintType = constraintType;
+            this.m_Solver = solver;
+        }
+
+        public virtual void Dispose()
+        {
+
+        }
+
+        public abstract IConstraintsBatchImpl CreateConstraintsBatch();
+
+
+        public abstract void RemoveBatch(IConstraintsBatchImpl batch);
+
+
+        public virtual int GetConstraintCount()
+        {
+            int count = 0;
+            if (batches == null) return count;
+
+            foreach (T batch in batches)
+                if (batch != null)
+                    count += batch.GetConstraintCount();
+
+            return count;
+        }
+
+        public JobHandle Initialize(JobHandle inputDeps, float substepTime)
+        {
+            // initialize all batches in parallel:
+            if (batches.Count > 0)
+            {
+                NativeArray<JobHandle> deps = new NativeArray<JobHandle>(batches.Count, Allocator.TempJob, NativeArrayOptions.UninitializedMemory);
+                for (int i = 0; i < batches.Count; ++i)
+                    deps[i] = batches[i].enabled ? batches[i].Initialize(inputDeps, substepTime) : inputDeps;
+
+                JobHandle result = JobHandle.CombineDependencies(deps);
+                deps.Dispose();
+
+                return result;
+            }
+
+            return inputDeps;
+        }
+
+        public JobHandle Project(JobHandle inputDeps, float stepTime, float substepTime, int substeps)
+        {
+            UnityEngine.Profiling.Profiler.BeginSample("Project");
+
+            var parameters = m_Solver.abstraction.GetConstraintParameters(m_ConstraintType);
+
+            switch(parameters.evaluationOrder)
+            {
+                case Oni.ConstraintParameters.EvaluationOrder.Sequential:
+                    inputDeps = EvaluateSequential(inputDeps, stepTime, substepTime, substeps);
+                break;
+
+                case Oni.ConstraintParameters.EvaluationOrder.Parallel:
+                    inputDeps = EvaluateParallel(inputDeps, stepTime, substepTime, substeps);
+                break;
+            }
+
+            UnityEngine.Profiling.Profiler.EndSample();
+            
+            return inputDeps;
+        }
+
+        protected virtual JobHandle EvaluateSequential(JobHandle inputDeps, float stepTime, float substepTime,int substeps)
+        {
+            // evaluate and apply all batches:
+            for (int i = 0; i < batches.Count; ++i)
+            {
+                if (batches[i].enabled)
+                {
+                    inputDeps = batches[i].Evaluate(inputDeps, stepTime, substepTime, substeps);
+                    inputDeps = batches[i].Apply(inputDeps, substepTime);
+                    m_Solver.ScheduleBatchedJobsIfNeeded();
+                }
+            }
+
+            return inputDeps;
+        }
+
+        protected virtual JobHandle EvaluateParallel(JobHandle inputDeps, float stepTime, float substepTime, int substeps)
+        {
+            // evaluate all batches:
+            for (int i = 0; i < batches.Count; ++i)
+                if (batches[i].enabled)
+                {
+                    inputDeps = batches[i].Evaluate(inputDeps, stepTime, substepTime, substeps);
+                    m_Solver.ScheduleBatchedJobsIfNeeded();
+                }
+
+            // then apply them:
+            for (int i = 0; i < batches.Count; ++i)
+                if (batches[i].enabled)
+                {
+                    inputDeps = batches[i].Apply(inputDeps, substepTime);
+                    m_Solver.ScheduleBatchedJobsIfNeeded();
+                }
+
+            return inputDeps;
+        }
+
+    }
+}
+#endif

Assets/Obi/Scripts/Common/Backends/Burst/Constraints/BurstConstraintsImpl.cs.meta

@@ -0,0 +1,11 @@
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Assets/Obi/Scripts/Common/Backends/Burst/Constraints/Chain.meta

@@ -0,0 +1,8 @@
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Assets/Obi/Scripts/Common/Backends/Burst/Constraints/Chain/BurstChainConstraints.cs

@@ -0,0 +1,26 @@
+#if (OBI_BURST && OBI_MATHEMATICS && OBI_COLLECTIONS)
+using System;
+
+namespace Obi
+{
+    public class BurstChainConstraints : BurstConstraintsImpl<BurstChainConstraintsBatch>
+    {
+        public BurstChainConstraints(BurstSolverImpl solver) : base(solver, Oni.ConstraintType.Chain)
+        {
+        }
+
+        public override IConstraintsBatchImpl CreateConstraintsBatch()
+        {
+            var dataBatch = new BurstChainConstraintsBatch(this);
+            batches.Add(dataBatch);
+            return dataBatch;
+        }
+
+        public override void RemoveBatch(IConstraintsBatchImpl batch)
+        {
+            batches.Remove(batch as BurstChainConstraintsBatch);
+            batch.Destroy();
+        }
+    }
+}
+#endif

Assets/Obi/Scripts/Common/Backends/Burst/Constraints/Chain/BurstChainConstraints.cs.meta

@@ -0,0 +1,11 @@
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Assets/Obi/Scripts/Common/Backends/Burst/Constraints/Chain/BurstChainConstraintsBatch.cs

@@ -0,0 +1,217 @@
+#if (OBI_BURST && OBI_MATHEMATICS && OBI_COLLECTIONS)
+using UnityEngine;
+using Unity.Jobs;
+using Unity.Collections;
+using Unity.Collections.LowLevel.Unsafe;
+using Unity.Mathematics;
+using Unity.Burst;
+using System.Collections;
+
+namespace Obi
+{
+    public class BurstChainConstraintsBatch : BurstConstraintsBatchImpl, IChainConstraintsBatchImpl
+    {
+        private NativeArray<int> firstIndex;
+        private NativeArray<int> numIndices;
+        private NativeArray<float2> restLengths;
+
+        public BurstChainConstraintsBatch(BurstChainConstraints constraints)
+        {
+            m_Constraints = constraints;
+            m_ConstraintType = Oni.ConstraintType.Chain;
+        }
+
+        public void SetChainConstraints(ObiNativeIntList particleIndices, ObiNativeVector2List restLengths, ObiNativeIntList firstIndex, ObiNativeIntList numIndices, int count)
+        {
+            this.particleIndices = particleIndices.AsNativeArray<int>();
+            this.firstIndex = firstIndex.AsNativeArray<int>();
+            this.numIndices = numIndices.AsNativeArray<int>();
+            this.restLengths = restLengths.AsNativeArray<float2>();
+            m_ConstraintCount = count;
+        }
+
+        public override JobHandle Evaluate(JobHandle inputDeps, float stepTime, float substepTime, int substeps)
+        {
+
+            var projectConstraints = new ChainConstraintsBatchJob()
+            {
+                particleIndices = particleIndices,
+                firstIndex = firstIndex,
+                numIndices = numIndices,
+                restLengths = restLengths,
+
+                positions = solverImplementation.positions,
+                invMasses = solverImplementation.invMasses,
+
+                deltas = solverImplementation.positionDeltas,
+                counts = solverImplementation.positionConstraintCounts
+            };
+
+            return projectConstraints.Schedule(m_ConstraintCount, 4, inputDeps);
+        }
+
+        public override JobHandle Apply(JobHandle inputDeps, float substepTime)
+        {
+            var parameters = solverAbstraction.GetConstraintParameters(m_ConstraintType);
+
+            var applyConstraints = new ApplyChainConstraintsBatchJob()
+            {
+                particleIndices = particleIndices,
+                firstIndex = firstIndex,
+                numIndices = numIndices,
+
+                positions = solverImplementation.positions,
+                deltas = solverImplementation.positionDeltas,
+                counts = solverImplementation.positionConstraintCounts,
+
+                sorFactor = parameters.SORFactor
+            };
+
+            return applyConstraints.Schedule(m_ConstraintCount, 8, inputDeps);
+        }
+
+        [BurstCompile]
+        public struct ChainConstraintsBatchJob : IJobParallelFor
+        {
+            [ReadOnly] public NativeArray<int> particleIndices;
+            [ReadOnly] public NativeArray<int> firstIndex;
+            [ReadOnly] public NativeArray<int> numIndices;
+            [ReadOnly] public NativeArray<float2> restLengths;
+
+            [ReadOnly] public NativeArray<float4> positions;
+            [ReadOnly] public NativeArray<float> invMasses;
+
+            [NativeDisableContainerSafetyRestriction][NativeDisableParallelForRestriction] public NativeArray<float4> deltas;
+            [NativeDisableContainerSafetyRestriction][NativeDisableParallelForRestriction] public NativeArray<int> counts;
+
+            public void Execute(int c)
+            {
+                int numEdges = numIndices[c] - 1;
+                int first = firstIndex[c];
+                float minLength = restLengths[c].y;
+                float maxLength = restLengths[c].y;
+
+                // (ni:constraint gradient, di:desired lenght)
+                NativeArray<float4> ni = new NativeArray<float4>(numEdges, Allocator.Temp);
+                NativeArray<float> di = new NativeArray<float>(numEdges, Allocator.Temp);
+
+                for (int i = 0; i < numEdges; ++i)
+                {
+                    int edge = first + i;
+
+                    float4 p1 = positions[particleIndices[edge]];
+                    float4 p2 = positions[particleIndices[edge+1]];
+                    float4 diff = p1 - p2;
+
+                    float distance = math.length(diff);
+                    float correction = 0;
+
+                    if (distance >= maxLength)
+                        correction = distance - maxLength;
+                    else if (distance <= minLength)
+                        correction = distance - minLength;
+
+                    di[i] = correction;
+                    ni[i] = new float4(diff/(distance + BurstMath.epsilon));
+                }
+
+                // calculate ai (subdiagonals), bi (diagonals) and ci (superdiagonals):
+                NativeArray<float3> diagonals = new NativeArray<float3>(numEdges, Allocator.Temp);
+
+                for (int i = 0; i < numEdges; ++i)
+                {
+                    int edge = first + i;
+
+                    float w_i_ = invMasses[particleIndices[edge]];
+                    float w__i = invMasses[particleIndices[edge+1]];
+
+                    float4 ni__ = (i > 0) ? ni[i - 1] : float4.zero;
+                    float4 n_i_ = ni[i];
+                    float4 n__i = (i < numEdges - 1) ? ni[i + 1] : float4.zero;
+
+                    diagonals[i] = new float3(
+                                    -w_i_ * math.dot(n_i_, ni__), // ai
+                                    w_i_ + w__i,                  // bi
+                                    -w__i * math.dot(n_i_, n__i));// ci
+                }
+
+                NativeArray<float2> sweep = new NativeArray<float2>(numEdges, Allocator.Temp);
+
+                // solve step #1, forward sweep:
+                for (int i = 0; i < numEdges; ++i)
+                {
+                    int edge = first + i;
+
+                    float cip_ = (i > 0) ? sweep[i - 1].x : 0;
+                    float dip_ = (i > 0) ? sweep[i - 1].y : 0;
+                    float den = diagonals[i].y - cip_ * diagonals[i].x;
+
+                    if (den != 0)
+                    {
+                        sweep[i] = new float2((diagonals[i].z / den),
+                                              (di[i] - dip_ * diagonals[i].x) / den);
+                    }
+                    else
+                        sweep[i] = float2.zero;
+                }
+
+                // solve step #2, backward sweep:
+                NativeArray<float> xi = new NativeArray<float>(numEdges, Allocator.Temp);
+                for (int i = numEdges - 1; i >= 0; --i)
+                {
+                    int edge = first + i;
+
+                    float xi_ = (i < numEdges - 1) ? xi[i + 1] : 0;
+                    xi[i] = sweep[i].y - sweep[i].x * xi_;
+                }
+
+                // calculate deltas:
+                for (int i = 0; i < numIndices[c]; ++i)
+                {
+                    int index = first + i;
+
+                    float4 ni__ = (i > 0) ? ni[i - 1] : float4.zero;
+                    float4 n_i_ = (i < numIndices[c] - 1) ? ni[i] : float4.zero;
+
+                    float xi_ = (i > 0) ? xi[i - 1] : 0;
+                    float nxi = (i < numIndices[c] - 1) ? xi[i] : 0;
+
+                    int p = particleIndices[index];
+                    deltas[p] -= invMasses[p] * (-ni__ * xi_ + n_i_ * nxi);
+                    counts[p]++;
+                }
+            }
+        }
+
+        [BurstCompile]
+        public struct ApplyChainConstraintsBatchJob : IJobParallelFor
+        {
+            [ReadOnly] public NativeArray<int> particleIndices;
+            [ReadOnly] public NativeArray<int> firstIndex;
+            [ReadOnly] public NativeArray<int> numIndices;
+            [ReadOnly] public float sorFactor;
+
+            [NativeDisableContainerSafetyRestriction] [NativeDisableParallelForRestriction] public NativeArray<float4> positions;
+            [NativeDisableContainerSafetyRestriction] [NativeDisableParallelForRestriction] public NativeArray<float4> deltas;
+            [NativeDisableContainerSafetyRestriction] [NativeDisableParallelForRestriction] public NativeArray<int> counts;
+
+            public void Execute(int i)
+            {
+                int first = firstIndex[i];
+                int last = first + numIndices[i];
+
+                for (int k = first; k < last; ++k)
+                {
+                    int p = particleIndices[k];
+                    if (counts[p] > 0)
+                    {
+                        positions[p] += deltas[p] * sorFactor / counts[p];
+                        deltas[p] = float4.zero;
+                        counts[p] = 0;
+                    }
+                }
+            }
+        }
+    }
+}
+#endif

Assets/Obi/Scripts/Common/Backends/Burst/Constraints/Chain/BurstChainConstraintsBatch.cs.meta

@@ -0,0 +1,11 @@
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Assets/Obi/Scripts/Common/Backends/Burst/Constraints/ColliderCollision.meta

@@ -0,0 +1,8 @@
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+guid: 0d7d6ac7f5b664d5cb7860b843e47fff
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Assets/Obi/Scripts/Common/Backends/Burst/Constraints/ColliderCollision/ApplyCollisionConstraintsJob.cs

@@ -0,0 +1,49 @@
+#if (OBI_BURST && OBI_MATHEMATICS && OBI_COLLECTIONS)
+using UnityEngine;
+using Unity.Jobs;
+using Unity.Collections;
+using Unity.Mathematics;
+using Unity.Burst;
+using System;
+using System.Collections;
+
+namespace Obi
+{
+
+    [BurstCompile]
+    public struct ApplyCollisionConstraintsBatchJob : IJob
+    {
+        [ReadOnly] public NativeArray<BurstContact> contacts;
+
+        [ReadOnly] public NativeArray<int> simplices;
+        [ReadOnly] public SimplexCounts simplexCounts;
+
+        [NativeDisableParallelForRestriction] public NativeArray<float4> positions;
+        [NativeDisableParallelForRestriction] public NativeArray<float4> deltas;
+        [NativeDisableParallelForRestriction] public NativeArray<int> counts;
+
+        [NativeDisableParallelForRestriction] public NativeArray<quaternion> orientations;
+        [NativeDisableParallelForRestriction] public NativeArray<quaternion> orientationDeltas;
+        [NativeDisableParallelForRestriction] public NativeArray<int> orientationCounts;
+
+        [ReadOnly] public Oni.ConstraintParameters constraintParameters;
+
+        public void Execute()
+        {
+            for (int i = 0; i < contacts.Length; ++i)
+            {
+                int simplexStart = simplexCounts.GetSimplexStartAndSize(contacts[i].bodyA, out int simplexSize);
+
+                for (int j = 0; j < simplexSize; ++j)
+                {
+                    int particleIndex = simplices[simplexStart + j];
+                    BurstConstraintsBatchImpl.ApplyPositionDelta(particleIndex, constraintParameters.SORFactor, ref positions, ref deltas, ref counts);
+                    BurstConstraintsBatchImpl.ApplyOrientationDelta(particleIndex, constraintParameters.SORFactor, ref orientations, ref orientationDeltas, ref orientationCounts);
+                }
+            }
+        }
+
+    }
+
+}
+#endif

Assets/Obi/Scripts/Common/Backends/Burst/Constraints/ColliderCollision/ApplyCollisionConstraintsJob.cs.meta

@@ -0,0 +1,11 @@
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Assets/Obi/Scripts/Common/Backends/Burst/Constraints/ColliderCollision/BurstColliderCollisionConstraints.cs

@@ -0,0 +1,33 @@
+#if (OBI_BURST && OBI_MATHEMATICS && OBI_COLLECTIONS)
+using System;
+
+namespace Obi
+{
+    public class BurstColliderCollisionConstraints : BurstConstraintsImpl<BurstColliderCollisionConstraintsBatch>
+    {
+        public BurstColliderCollisionConstraints(BurstSolverImpl solver) : base(solver, Oni.ConstraintType.Collision)
+        {
+        }
+
+        public override IConstraintsBatchImpl CreateConstraintsBatch()
+        {
+            var dataBatch = new BurstColliderCollisionConstraintsBatch(this);
+            batches.Add(dataBatch);
+            return dataBatch;
+        }
+
+        public override void RemoveBatch(IConstraintsBatchImpl batch)
+        {
+            batches.Remove(batch as BurstColliderCollisionConstraintsBatch);
+            batch.Destroy();
+        }
+
+        public override int GetConstraintCount()
+        {
+            if (!((BurstSolverImpl)solver).colliderContacts.IsCreated)
+                return 0;
+            return ((BurstSolverImpl)solver).colliderContacts.Length;
+        }
+    }
+}
+#endif

Assets/Obi/Scripts/Common/Backends/Burst/Constraints/ColliderCollision/BurstColliderCollisionConstraints.cs.meta

@@ -0,0 +1,11 @@
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Assets/Obi/Scripts/Common/Backends/Burst/Constraints/ColliderCollision/BurstColliderCollisionConstraintsBatch.cs

@@ -0,0 +1,330 @@
+#if (OBI_BURST && OBI_MATHEMATICS && OBI_COLLECTIONS)
+using UnityEngine;
+using Unity.Jobs;
+using Unity.Collections;
+using Unity.Collections.LowLevel.Unsafe;
+using Unity.Mathematics;
+using Unity.Burst;
+using System.Collections;
+
+namespace Obi
+{
+    public class BurstColliderCollisionConstraintsBatch : BurstConstraintsBatchImpl, IColliderCollisionConstraintsBatchImpl
+    {
+        public BurstColliderCollisionConstraintsBatch(BurstColliderCollisionConstraints constraints)
+        {
+            m_Constraints = constraints;
+            m_ConstraintType = Oni.ConstraintType.Collision;
+        }
+
+        public override JobHandle Initialize(JobHandle inputDeps, float substepTime)
+        {
+            var updateContacts = new UpdateContactsJob()
+            {
+                prevPositions = solverImplementation.prevPositions,
+                prevOrientations = solverImplementation.prevOrientations,
+                velocities = solverImplementation.velocities,
+                radii = solverImplementation.principalRadii,
+                invMasses = solverImplementation.invMasses,
+                invInertiaTensors = solverImplementation.invInertiaTensors,
+                particleMaterialIndices = solverImplementation.collisionMaterials,
+                collisionMaterials = ObiColliderWorld.GetInstance().collisionMaterials.AsNativeArray<BurstCollisionMaterial>(),
+
+                simplices = solverImplementation.simplices,
+                simplexCounts = solverImplementation.simplexCounts,
+
+                shapes = ObiColliderWorld.GetInstance().colliderShapes.AsNativeArray<BurstColliderShape>(),
+                transforms = ObiColliderWorld.GetInstance().colliderTransforms.AsNativeArray<BurstAffineTransform>(),
+                rigidbodies = ObiColliderWorld.GetInstance().rigidbodies.AsNativeArray<BurstRigidbody>(),
+                rigidbodyLinearDeltas = solverImplementation.abstraction.rigidbodyLinearDeltas.AsNativeArray<float4>(),
+                rigidbodyAngularDeltas = solverImplementation.abstraction.rigidbodyAngularDeltas.AsNativeArray<float4>(),
+
+                contacts = ((BurstSolverImpl)constraints.solver).colliderContacts,
+                inertialFrame = ((BurstSolverImpl)constraints.solver).inertialFrame
+            };
+            return updateContacts.Schedule(((BurstSolverImpl)constraints.solver).colliderContacts.Length, 128, inputDeps);
+        }
+
+        public override JobHandle Evaluate(JobHandle inputDeps, float stepTime, float substepTime, int substeps)
+        {
+            var parameters = solverAbstraction.GetConstraintParameters(m_ConstraintType);
+
+            var projectConstraints = new CollisionConstraintsBatchJob()
+            {
+                positions = solverImplementation.positions,
+                prevPositions = solverImplementation.prevPositions,
+                orientations = solverImplementation.orientations,
+                prevOrientations = solverImplementation.prevOrientations,
+                invMasses = solverImplementation.invMasses,
+                radii = solverImplementation.principalRadii,
+                particleMaterialIndices = solverImplementation.collisionMaterials,
+
+                simplices = solverImplementation.simplices,
+                simplexCounts = solverImplementation.simplexCounts,
+
+                shapes = ObiColliderWorld.GetInstance().colliderShapes.AsNativeArray<BurstColliderShape>(),
+                transforms = ObiColliderWorld.GetInstance().colliderTransforms.AsNativeArray<BurstAffineTransform>(),
+                collisionMaterials = ObiColliderWorld.GetInstance().collisionMaterials.AsNativeArray<BurstCollisionMaterial>(),
+                rigidbodies = ObiColliderWorld.GetInstance().rigidbodies.AsNativeArray<BurstRigidbody>(),
+                rigidbodyLinearDeltas = solverImplementation.abstraction.rigidbodyLinearDeltas.AsNativeArray<float4>(),
+                rigidbodyAngularDeltas = solverImplementation.abstraction.rigidbodyAngularDeltas.AsNativeArray<float4>(),
+
+                deltas = solverAbstraction.positionDeltas.AsNativeArray<float4>(),
+                counts = solverAbstraction.positionConstraintCounts.AsNativeArray<int>(),
+
+                contacts = ((BurstSolverImpl)constraints.solver).colliderContacts,
+                inertialFrame = ((BurstSolverImpl)constraints.solver).inertialFrame,
+                constraintParameters = parameters,
+                solverParameters = solverAbstraction.parameters,
+                substeps = substeps,
+                stepTime = stepTime,
+                substepTime = substepTime
+            };
+            return projectConstraints.Schedule(inputDeps);
+        }
+
+        public override JobHandle Apply(JobHandle inputDeps, float substepTime)
+        {
+            var parameters = solverAbstraction.GetConstraintParameters(m_ConstraintType);
+
+            var applyConstraints = new ApplyCollisionConstraintsBatchJob()
+            {
+                contacts = ((BurstSolverImpl)constraints.solver).colliderContacts,
+
+                simplices = solverImplementation.simplices,
+                simplexCounts = solverImplementation.simplexCounts,
+
+                positions = solverImplementation.positions,
+                deltas = solverImplementation.positionDeltas,
+                counts = solverImplementation.positionConstraintCounts,
+                orientations = solverImplementation.orientations,
+                orientationDeltas = solverImplementation.orientationDeltas,
+                orientationCounts = solverImplementation.orientationConstraintCounts,
+                constraintParameters = parameters
+            };
+
+            return applyConstraints.Schedule(inputDeps);
+        }
+
+        /**
+         * Updates contact data (such as contact distance) at the beginning of each substep. This is
+         * necessary because contacts are generalted only once at the beginning of each step, not every substep.
+         */
+        [BurstCompile]
+        public struct UpdateContactsJob : IJobParallelFor
+        {
+            [ReadOnly] public NativeArray<float4> prevPositions;
+            [ReadOnly] public NativeArray<quaternion> prevOrientations;
+            [ReadOnly] public NativeArray<float4> velocities;
+            [ReadOnly] public NativeArray<float4> radii;
+            [ReadOnly] public NativeArray<float> invMasses;
+            [ReadOnly] public NativeArray<float4> invInertiaTensors;
+
+            [ReadOnly] public NativeArray<int> particleMaterialIndices;
+            [ReadOnly] public NativeArray<BurstCollisionMaterial> collisionMaterials;
+
+            // simplex arrays:
+            [ReadOnly] public NativeArray<int> simplices;
+            [ReadOnly] public SimplexCounts simplexCounts;
+
+            [ReadOnly] public NativeArray<BurstColliderShape> shapes;
+            [ReadOnly] public NativeArray<BurstAffineTransform> transforms;
+            [ReadOnly] public NativeArray<BurstRigidbody> rigidbodies;
+            [ReadOnly] public NativeArray<float4> rigidbodyLinearDeltas;
+            [ReadOnly] public NativeArray<float4> rigidbodyAngularDeltas;
+
+            public NativeArray<BurstContact> contacts;
+            [ReadOnly] public BurstInertialFrame inertialFrame;
+
+            public void Execute(int i)
+            {
+                var contact = contacts[i];
+
+                int simplexStart = simplexCounts.GetSimplexStartAndSize(contact.bodyA, out int simplexSize);
+
+                // get the material from the first particle in the simplex:
+                int aMaterialIndex = particleMaterialIndices[simplices[simplexStart]];
+                bool rollingContacts = aMaterialIndex >= 0 ? collisionMaterials[aMaterialIndex].rollingContacts > 0 : false;
+
+                float4 relativeVelocity = float4.zero;
+                float4 simplexPrevPosition = float4.zero;
+                quaternion simplexPrevOrientation = new quaternion(0, 0, 0, 0);
+                float simplexInvMass = 0;
+                float4 simplexInvInertia = float4.zero;
+                float simplexRadius = 0;
+
+                for (int j = 0; j < simplexSize; ++j)
+                {
+                    int particleIndex = simplices[simplexStart + j];
+                    relativeVelocity += velocities[particleIndex]    * contact.pointA[j];
+                    simplexPrevPosition += prevPositions[particleIndex] * contact.pointA[j];
+                    simplexPrevOrientation.value += prevOrientations[particleIndex].value * contact.pointA[j];
+                    simplexInvMass += invMasses[particleIndex] * contact.pointA[j];
+                    simplexInvInertia += invInertiaTensors[particleIndex] * contact.pointA[j];
+                    simplexRadius += BurstMath.EllipsoidRadius(contact.normal, prevOrientations[particleIndex], radii[particleIndex].xyz) * contact.pointA[j];
+                }
+
+                // if there's a rigidbody present, subtract its velocity from the relative velocity:
+                int rigidbodyIndex = shapes[contact.bodyB].rigidbodyIndex;
+                if (rigidbodyIndex >= 0)
+                {
+                    relativeVelocity -= BurstMath.GetRigidbodyVelocityAtPoint(rigidbodyIndex, contact.pointB, rigidbodies, rigidbodyLinearDeltas, rigidbodyAngularDeltas, inertialFrame.frame);
+
+                    int bMaterialIndex = shapes[contact.bodyB].materialIndex;
+                    rollingContacts |= bMaterialIndex >= 0 ? collisionMaterials[bMaterialIndex].rollingContacts > 0 : false;
+                }
+
+                // update contact distance
+                contact.distance = math.dot(simplexPrevPosition - contact.pointB, contact.normal) - simplexRadius;
+
+                // calculate contact point in A's surface:
+                float4 contactPoint = contact.pointB + contact.normal * contact.distance;
+
+                // update contact orthonormal basis:
+                contact.CalculateBasis(relativeVelocity);
+
+                // calculate A's contact mass.
+                contact.CalculateContactMassesA(simplexInvMass, simplexInvInertia, simplexPrevPosition, simplexPrevOrientation, contactPoint, rollingContacts);
+
+                // calculate B's contact mass.
+                if (rigidbodyIndex >= 0)
+                    contact.CalculateContactMassesB(rigidbodies[rigidbodyIndex], inertialFrame.frame);
+
+                contacts[i] = contact;
+            }
+        }
+
+        [BurstCompile]
+        public struct CollisionConstraintsBatchJob : IJob
+        {
+            [ReadOnly] public NativeArray<float4> prevPositions;
+            [ReadOnly] public NativeArray<quaternion> orientations;
+            [ReadOnly] public NativeArray<quaternion> prevOrientations;
+            [ReadOnly] public NativeArray<float> invMasses;
+            [ReadOnly] public NativeArray<float4> radii;
+            [ReadOnly] public NativeArray<int> particleMaterialIndices;
+
+            // simplex arrays:
+            [ReadOnly] public NativeArray<int> simplices;
+            [ReadOnly] public SimplexCounts simplexCounts;
+
+            [ReadOnly] public NativeArray<BurstColliderShape> shapes;
+            [ReadOnly] public NativeArray<BurstAffineTransform> transforms;
+            [ReadOnly] public NativeArray<BurstCollisionMaterial> collisionMaterials;
+            [ReadOnly] public NativeArray<BurstRigidbody> rigidbodies;
+            public NativeArray<float4> rigidbodyLinearDeltas;
+            public NativeArray<float4> rigidbodyAngularDeltas;
+
+            [NativeDisableContainerSafetyRestriction] [NativeDisableParallelForRestriction] public NativeArray<float4> positions;
+            [NativeDisableContainerSafetyRestriction] [NativeDisableParallelForRestriction] public NativeArray<float4> deltas;
+            [NativeDisableContainerSafetyRestriction] [NativeDisableParallelForRestriction] public NativeArray<int> counts;
+
+            public NativeArray<BurstContact> contacts;
+            [ReadOnly] public BurstInertialFrame inertialFrame;
+            [ReadOnly] public Oni.ConstraintParameters constraintParameters;
+            [ReadOnly] public Oni.SolverParameters solverParameters;
+            [ReadOnly] public float stepTime;
+            [ReadOnly] public float substepTime;
+            [ReadOnly] public int substeps;
+
+            public void Execute()
+            {
+                for (int i = 0; i < contacts.Length; ++i)
+                {
+                    var contact = contacts[i];
+
+                    int simplexStart = simplexCounts.GetSimplexStartAndSize(contact.bodyA, out int simplexSize);
+                    int colliderIndex = contact.bodyB;
+
+                    // Skip contacts involving triggers:
+                    if (shapes[colliderIndex].flags > 0)
+                        continue;
+
+                    // Get the rigidbody index (might be < 0, in that case there's no rigidbody present)
+                    int rigidbodyIndex = shapes[colliderIndex].rigidbodyIndex;
+
+                    // Combine collision materials (use material from first particle in simplex)
+                    BurstCollisionMaterial material = CombineCollisionMaterials(simplices[simplexStart], colliderIndex);
+
+                    // Get relative velocity at contact point.
+                    // As we do not consider true ellipses for collision detection, particle contact points are never off-axis.
+                    // So particle angular velocity does not contribute to normal impulses, and we can skip it.
+                    float4 simplexPosition = float4.zero;
+                    float4 simplexPrevPosition = float4.zero;
+                    float simplexRadius = 0;
+
+                    for (int j = 0; j < simplexSize; ++j)
+                    {
+                        int particleIndex = simplices[simplexStart + j];
+                        simplexPosition += positions[particleIndex] * contact.pointA[j];
+                        simplexPrevPosition += prevPositions[particleIndex] * contact.pointA[j];
+                        simplexRadius += BurstMath.EllipsoidRadius(contact.normal, orientations[particleIndex], radii[particleIndex].xyz) * contact.pointA[j];
+                    }
+
+                    // project position to the end of the full step:
+                    float4 posA = math.lerp(simplexPrevPosition, simplexPosition, substeps);
+                    posA += -contact.normal * simplexRadius;
+
+                    float4 posB = contact.pointB;
+
+                    if (rigidbodyIndex >= 0)
+                        posB += BurstMath.GetRigidbodyVelocityAtPoint(rigidbodyIndex, contact.pointB, rigidbodies, rigidbodyLinearDeltas, rigidbodyAngularDeltas, inertialFrame.frame) * stepTime;
+
+                    // adhesion:
+                    float lambda = contact.SolveAdhesion(posA, posB, material.stickDistance, material.stickiness, stepTime);
+
+                    // depenetration:
+                    lambda += contact.SolvePenetration(posA, posB, solverParameters.maxDepenetration * stepTime);
+
+                    // Apply normal impulse to both simplex and rigidbody:
+                    if (math.abs(lambda) > BurstMath.epsilon)
+                    {
+                        float4 delta = lambda * contact.normal * BurstMath.BaryScale(contact.pointA) / substeps;
+                        for (int j = 0; j < simplexSize; ++j)
+                        {
+                            int particleIndex = simplices[simplexStart + j];
+                            deltas[particleIndex] += delta * invMasses[particleIndex] * contact.pointA[j];
+                            counts[particleIndex]++;
+                        }
+
+                        // Apply position deltas immediately, if using sequential evaluation:
+                        if (constraintParameters.evaluationOrder == Oni.ConstraintParameters.EvaluationOrder.Sequential)
+                        {
+                            for (int j = 0; j < simplexSize; ++j)
+                            {
+                                int particleIndex = simplices[simplexStart + j];
+                                BurstConstraintsBatchImpl.ApplyPositionDelta(particleIndex, constraintParameters.SORFactor, ref positions, ref deltas, ref counts);
+                            }
+                        }
+
+                        if (rigidbodyIndex >= 0)
+                        {
+                            BurstMath.ApplyImpulse(rigidbodyIndex, -lambda / stepTime * contact.normal, contact.pointB, rigidbodies, rigidbodyLinearDeltas, rigidbodyAngularDeltas, inertialFrame.frame);
+                        }
+                    }
+
+                    contacts[i] = contact;
+                }
+            }
+
+            private BurstCollisionMaterial CombineCollisionMaterials(int entityA, int entityB)
+            {
+                // Combine collision materials:
+                int particleMaterialIndex = particleMaterialIndices[entityA];
+                int colliderMaterialIndex = shapes[entityB].materialIndex;
+
+                if (colliderMaterialIndex >= 0 && particleMaterialIndex >= 0)
+                    return BurstCollisionMaterial.CombineWith(collisionMaterials[particleMaterialIndex], collisionMaterials[colliderMaterialIndex]);
+                else if (particleMaterialIndex >= 0)
+                    return collisionMaterials[particleMaterialIndex];
+                else if (colliderMaterialIndex >= 0)
+                    return collisionMaterials[colliderMaterialIndex];
+
+                return new BurstCollisionMaterial();
+            }
+        }
+
+
+    }
+}
+#endif

Assets/Obi/Scripts/Common/Backends/Burst/Constraints/ColliderCollision/BurstColliderCollisionConstraintsBatch.cs.meta

@@ -0,0 +1,11 @@
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Assets/Obi/Scripts/Common/Backends/Burst/Constraints/ColliderCollision/BurstColliderFrictionConstraints.cs

@@ -0,0 +1,35 @@
+#if (OBI_BURST && OBI_MATHEMATICS && OBI_COLLECTIONS)
+using System;
+
+namespace Obi
+{
+    public class BurstColliderFrictionConstraints : BurstConstraintsImpl<BurstColliderFrictionConstraintsBatch>
+    {
+        public BurstColliderFrictionConstraints(BurstSolverImpl solver) : base(solver, Oni.ConstraintType.Friction)
+        {
+        }
+
+        public override IConstraintsBatchImpl CreateConstraintsBatch()
+        {
+            var dataBatch = new BurstColliderFrictionConstraintsBatch(this);
+            batches.Add(dataBatch);
+            return dataBatch;
+        }
+
+
+        public override void RemoveBatch(IConstraintsBatchImpl batch)
+        {
+            batches.Remove(batch as BurstColliderFrictionConstraintsBatch);
+            batch.Destroy();
+        }
+
+        public override int GetConstraintCount()
+        {
+            if (!((BurstSolverImpl)solver).colliderContacts.IsCreated)
+                return 0;
+            return ((BurstSolverImpl)solver).colliderContacts.Length;
+        }
+    }
+}
+#endif
+

Assets/Obi/Scripts/Common/Backends/Burst/Constraints/ColliderCollision/BurstColliderFrictionConstraints.cs.meta

@@ -0,0 +1,11 @@
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Assets/Obi/Scripts/Common/Backends/Burst/Constraints/ColliderCollision/BurstColliderFrictionConstraintsBatch.cs

@@ -0,0 +1,284 @@
+#if (OBI_BURST && OBI_MATHEMATICS && OBI_COLLECTIONS)
+using Unity.Jobs;
+using Unity.Collections;
+using Unity.Collections.LowLevel.Unsafe;
+using Unity.Mathematics;
+using Unity.Burst;
+
+namespace Obi
+{
+    public class BurstColliderFrictionConstraintsBatch : BurstConstraintsBatchImpl, IColliderFrictionConstraintsBatchImpl
+    {
+        public BurstColliderFrictionConstraintsBatch(BurstColliderFrictionConstraints constraints)
+        {
+            m_Constraints = constraints;
+            m_ConstraintType = Oni.ConstraintType.Friction;
+        }
+
+        public override JobHandle Initialize(JobHandle inputDeps, float substepTime)
+        {
+            return inputDeps;
+        }
+
+        public override JobHandle Evaluate(JobHandle inputDeps, float stepTime, float substepTime, int substeps)
+        {
+            if (!((BurstSolverImpl)constraints.solver).colliderContacts.IsCreated)
+                return inputDeps;
+
+            var projectConstraints = new FrictionConstraintsBatchJob()
+            {
+                positions = solverImplementation.positions,
+                prevPositions = solverImplementation.prevPositions,
+                orientations = solverImplementation.orientations,
+                prevOrientations = solverImplementation.prevOrientations,
+
+                invMasses = solverImplementation.invMasses,
+                invInertiaTensors = solverImplementation.invInertiaTensors,
+                radii = solverImplementation.principalRadii,
+                particleMaterialIndices = solverImplementation.collisionMaterials,
+
+                simplices = solverImplementation.simplices,
+                simplexCounts = solverImplementation.simplexCounts,
+
+                shapes = ObiColliderWorld.GetInstance().colliderShapes.AsNativeArray<BurstColliderShape>(),
+                transforms = ObiColliderWorld.GetInstance().colliderTransforms.AsNativeArray<BurstAffineTransform>(),
+                collisionMaterials = ObiColliderWorld.GetInstance().collisionMaterials.AsNativeArray<BurstCollisionMaterial>(),
+                rigidbodies = ObiColliderWorld.GetInstance().rigidbodies.AsNativeArray<BurstRigidbody>(),
+                rigidbodyLinearDeltas = solverImplementation.abstraction.rigidbodyLinearDeltas.AsNativeArray<float4>(),
+                rigidbodyAngularDeltas = solverImplementation.abstraction.rigidbodyAngularDeltas.AsNativeArray<float4>(),
+
+                deltas = solverImplementation.positionDeltas,
+                counts = solverImplementation.positionConstraintCounts,
+                orientationDeltas = solverImplementation.orientationDeltas,
+                orientationCounts = solverImplementation.orientationConstraintCounts,
+
+                contacts = ((BurstSolverImpl)constraints.solver).colliderContacts,
+                inertialFrame = ((BurstSolverImpl)constraints.solver).inertialFrame,
+                substeps = substeps,
+                stepTime = stepTime,
+                substepTime = substepTime
+            };
+            return projectConstraints.Schedule(inputDeps);
+        }
+
+        public override JobHandle Apply(JobHandle inputDeps, float substepTime)
+        {
+            if (!((BurstSolverImpl)constraints.solver).colliderContacts.IsCreated)
+                return inputDeps;
+
+            var parameters = solverAbstraction.GetConstraintParameters(m_ConstraintType);
+
+            var applyConstraints = new ApplyCollisionConstraintsBatchJob()
+            {
+                contacts = ((BurstSolverImpl)constraints.solver).colliderContacts,
+
+                simplices = solverImplementation.simplices,
+                simplexCounts = solverImplementation.simplexCounts,
+
+                positions = solverImplementation.positions,
+                deltas = solverImplementation.positionDeltas,
+                counts = solverImplementation.positionConstraintCounts,
+                orientations = solverImplementation.orientations,
+                orientationDeltas = solverImplementation.orientationDeltas,
+                orientationCounts = solverImplementation.orientationConstraintCounts,
+                constraintParameters = parameters
+            };
+
+            return applyConstraints.Schedule(inputDeps);
+        }
+
+        [BurstCompile]
+        public struct FrictionConstraintsBatchJob : IJob
+        {
+            [ReadOnly] public NativeArray<float4> positions;
+            [ReadOnly] public NativeArray<float4> prevPositions;
+            [ReadOnly] public NativeArray<quaternion> orientations;
+            [ReadOnly] public NativeArray<quaternion> prevOrientations;
+
+            [ReadOnly] public NativeArray<float> invMasses;
+            [ReadOnly] public NativeArray<float4> invInertiaTensors;
+            [ReadOnly] public NativeArray<float4> radii;
+            [ReadOnly] public NativeArray<int> particleMaterialIndices;
+
+            // simplex arrays:
+            [ReadOnly] public NativeArray<int> simplices;
+            [ReadOnly] public SimplexCounts simplexCounts;
+
+            [ReadOnly] public NativeArray<BurstColliderShape> shapes;
+            [ReadOnly] public NativeArray<BurstAffineTransform> transforms;
+            [ReadOnly] public NativeArray<BurstCollisionMaterial> collisionMaterials;
+            [ReadOnly] public NativeArray<BurstRigidbody> rigidbodies;
+            public NativeArray<float4> rigidbodyLinearDeltas;
+            public NativeArray<float4> rigidbodyAngularDeltas;
+
+            [NativeDisableContainerSafetyRestriction] [NativeDisableParallelForRestriction] public NativeArray<float4> deltas;
+            [NativeDisableContainerSafetyRestriction] [NativeDisableParallelForRestriction] public NativeArray<int> counts;
+
+            [NativeDisableContainerSafetyRestriction] [NativeDisableParallelForRestriction] public NativeArray<quaternion> orientationDeltas;
+            [NativeDisableContainerSafetyRestriction] [NativeDisableParallelForRestriction] public NativeArray<int> orientationCounts;
+
+            public NativeArray<BurstContact> contacts;
+            [ReadOnly] public BurstInertialFrame inertialFrame;
+            [ReadOnly] public float stepTime;
+            [ReadOnly] public float substepTime;
+            [ReadOnly] public int substeps;
+
+            public void Execute()
+            {
+                for (int i = 0; i < contacts.Length; ++i)
+                {
+                    var contact = contacts[i];
+
+                    // Get the indices of the particle and collider involved in this contact:
+                    int simplexStart = simplexCounts.GetSimplexStartAndSize(contact.bodyA, out int simplexSize);
+                    int colliderIndex = contact.bodyB;
+
+                    // Skip contacts involving triggers:
+                    if (shapes[colliderIndex].flags > 0)
+                        continue;
+
+                    // Get the rigidbody index (might be < 0, in that case there's no rigidbody present)
+                    int rigidbodyIndex = shapes[colliderIndex].rigidbodyIndex;
+
+                    // Combine collision materials (use material from first particle in simplex)
+                    BurstCollisionMaterial material = CombineCollisionMaterials(simplices[simplexStart], colliderIndex);
+
+                    // Calculate relative velocity:
+                    float4 rA = float4.zero, rB = float4.zero;
+
+                    float4 prevPositionA = float4.zero;
+                    float4 linearVelocityA = float4.zero;
+                    float4 angularVelocityA = float4.zero;
+                    float4 invInertiaTensorA = float4.zero;
+                    quaternion orientationA = new quaternion(0, 0, 0, 0);
+                    float simplexRadiusA = 0;
+
+                    for (int j = 0; j < simplexSize; ++j)
+                    {
+                        int particleIndex = simplices[simplexStart + j];
+                        prevPositionA    += prevPositions[particleIndex] * contact.pointA[j];
+                        linearVelocityA  += BurstIntegration.DifferentiateLinear(positions[particleIndex],prevPositions[particleIndex], substepTime) * contact.pointA[j];
+                        angularVelocityA += BurstIntegration.DifferentiateAngular(orientations[particleIndex], prevOrientations[particleIndex], substepTime) * contact.pointA[j];
+                        invInertiaTensorA += invInertiaTensors[particleIndex] * contact.pointA[j];
+                        orientationA.value += orientations[particleIndex].value * contact.pointA[j];
+                        simplexRadiusA += BurstMath.EllipsoidRadius(contact.normal, prevOrientations[particleIndex], radii[particleIndex].xyz) * contact.pointA[j];
+                    }
+
+                    float4 relativeVelocity = linearVelocityA;
+
+                    // Add particle angular velocity if rolling contacts are enabled:
+                    if (material.rollingContacts > 0)
+                    {
+                        rA = -contact.normal * simplexRadiusA;
+                        relativeVelocity += new float4(math.cross(angularVelocityA.xyz, rA.xyz), 0);
+                    }
+
+                    // Subtract rigidbody velocity:
+                    if (rigidbodyIndex >= 0)
+                    {
+                        // Note: unlike rA, that is expressed in solver space, rB is expressed in world space.
+                        rB = inertialFrame.frame.TransformPoint(contact.pointB) - rigidbodies[rigidbodyIndex].com;
+                        relativeVelocity -= BurstMath.GetRigidbodyVelocityAtPoint(rigidbodyIndex, contact.pointB, rigidbodies, rigidbodyLinearDeltas, rigidbodyAngularDeltas, inertialFrame.frame);
+                    }
+
+                    // Determine impulse magnitude:
+                    float2 impulses = contact.SolveFriction(relativeVelocity, material.staticFriction, material.dynamicFriction, stepTime);
+
+                    if (math.abs(impulses.x) > BurstMath.epsilon || math.abs(impulses.y) > BurstMath.epsilon)
+                    {
+                        float4 tangentImpulse   = impulses.x * contact.tangent;
+                        float4 bitangentImpulse = impulses.y * contact.bitangent;
+                        float4 totalImpulse = tangentImpulse + bitangentImpulse;
+
+                        float baryScale = BurstMath.BaryScale(contact.pointA);
+                        for (int j = 0; j < simplexSize; ++j)
+                        {
+                            int particleIndex = simplices[simplexStart + j];
+                            //(tangentImpulse * contact.tangentInvMassA + bitangentImpulse * contact.bitangentInvMassA) * dt;
+                            deltas[particleIndex] += (tangentImpulse * contact.tangentInvMassA + bitangentImpulse * contact.bitangentInvMassA) * substepTime * contact.pointA[j] * baryScale; 
+                            counts[particleIndex]++;
+                        }
+
+                        if (rigidbodyIndex >= 0)
+                        {
+                            BurstMath.ApplyImpulse(rigidbodyIndex, -totalImpulse, contact.pointB, rigidbodies, rigidbodyLinearDeltas, rigidbodyAngularDeltas, inertialFrame.frame);
+                        }
+
+                        // Rolling contacts:
+                        if (material.rollingContacts > 0)
+                        {
+                            // Calculate angular velocity deltas due to friction impulse:
+                            float4x4 solverInertiaA = BurstMath.TransformInertiaTensor(invInertiaTensorA, orientationA);
+
+                            float4 angVelDeltaA = math.mul(solverInertiaA, new float4(math.cross(rA.xyz, totalImpulse.xyz), 0));
+                            float4 angVelDeltaB = float4.zero;
+
+                            // Final angular velocities, after adding the deltas:
+                            angularVelocityA += angVelDeltaA;
+                            float4 angularVelocityB = float4.zero;
+
+                            // Calculate weights (inverse masses):
+                            float invMassA = math.length(math.mul(solverInertiaA, math.normalizesafe(angularVelocityA)));
+                            float invMassB = 0;
+
+                            if (rigidbodyIndex >= 0)
+                            {
+                                angVelDeltaB = math.mul(-rigidbodies[rigidbodyIndex].inverseInertiaTensor, new float4(math.cross(rB.xyz, totalImpulse.xyz), 0));
+                                angularVelocityB = rigidbodies[rigidbodyIndex].angularVelocity + angVelDeltaB;
+                                invMassB = math.length(math.mul(rigidbodies[rigidbodyIndex].inverseInertiaTensor, math.normalizesafe(angularVelocityB)));
+                            }
+
+                            // Calculate rolling axis and angular velocity deltas:
+                            float4 rollAxis = float4.zero;
+                            float rollingImpulse = contact.SolveRollingFriction(angularVelocityA, angularVelocityB, material.rollingFriction, invMassA, invMassB, ref rollAxis);
+                            angVelDeltaA += rollAxis * rollingImpulse * invMassA;
+                            angVelDeltaB -= rollAxis * rollingImpulse * invMassB;
+
+                            // Apply orientation delta to particles:
+                            quaternion orientationDelta = BurstIntegration.AngularVelocityToSpinQuaternion(orientationA, angVelDeltaA, substepTime);
+
+                            for (int j = 0; j < simplexSize; ++j)
+                            {
+                                int particleIndex = simplices[simplexStart + j];
+                                quaternion qA = orientationDeltas[particleIndex];
+                                qA.value += orientationDelta.value;
+                                orientationDeltas[particleIndex] = qA;
+                                orientationCounts[particleIndex]++;
+                            }
+
+                            // Apply angular velocity delta to rigidbody:
+                            if (rigidbodyIndex >= 0)
+                            {
+                                float4 angularDelta = rigidbodyAngularDeltas[rigidbodyIndex];
+                                angularDelta += angVelDeltaB;
+                                rigidbodyAngularDeltas[rigidbodyIndex] = angularDelta;
+                            }
+                        }
+                    }
+
+                    contacts[i] = contact;
+                }
+            }
+
+            private BurstCollisionMaterial CombineCollisionMaterials(int entityA, int entityB)
+            {
+                // Combine collision materials:
+                int particleMaterialIndex = particleMaterialIndices[entityA];
+                int colliderMaterialIndex = shapes[entityB].materialIndex;
+
+                if (colliderMaterialIndex >= 0 && particleMaterialIndex >= 0)
+                    return BurstCollisionMaterial.CombineWith(collisionMaterials[particleMaterialIndex], collisionMaterials[colliderMaterialIndex]);
+                else if (particleMaterialIndex >= 0)
+                    return collisionMaterials[particleMaterialIndex];
+                else if (colliderMaterialIndex >= 0)
+                    return collisionMaterials[colliderMaterialIndex];
+
+                return new BurstCollisionMaterial();
+            }
+
+        }
+
+
+    }
+}
+#endif

Assets/Obi/Scripts/Common/Backends/Burst/Constraints/ColliderCollision/BurstColliderFrictionConstraintsBatch.cs.meta

@@ -0,0 +1,11 @@
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Assets/Obi/Scripts/Common/Backends/Burst/Constraints/Density.meta

@@ -0,0 +1,8 @@
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Assets/Obi/Scripts/Common/Backends/Burst/Constraints/Density/BurstDensityConstraints.cs

@@ -0,0 +1,452 @@
+#if (OBI_BURST && OBI_MATHEMATICS && OBI_COLLECTIONS)
+using System;
+using Unity.Jobs;
+using Unity.Burst;
+using Unity.Collections;
+using Unity.Collections.LowLevel.Unsafe;
+using Unity.Mathematics;
+
+namespace Obi
+{
+    public class BurstDensityConstraints : BurstConstraintsImpl<BurstDensityConstraintsBatch>
+    {
+        public NativeList<int> fluidParticles;
+
+        public NativeArray<float4> eta;
+        public NativeArray<float4> smoothPositions;
+        public NativeArray<float3x3> anisotropies;
+
+        public BurstDensityConstraints(BurstSolverImpl solver) : base(solver, Oni.ConstraintType.Density)
+        {
+            fluidParticles = new NativeList<int>(Allocator.Persistent);
+        }
+
+        public override IConstraintsBatchImpl CreateConstraintsBatch()
+        {
+            var dataBatch = new BurstDensityConstraintsBatch(this);
+            batches.Add(dataBatch);
+            return dataBatch;
+        }
+
+        public override void Dispose()
+        {
+            fluidParticles.Dispose();
+        }
+
+        public override void RemoveBatch(IConstraintsBatchImpl batch)
+        {
+            batches.Remove(batch as BurstDensityConstraintsBatch);
+            batch.Destroy();
+        }
+
+        protected override JobHandle EvaluateSequential(JobHandle inputDeps, float stepTime, float substepTime, int substeps)
+        {
+            return EvaluateParallel(inputDeps, stepTime, substepTime, substeps);
+        }
+
+        protected override JobHandle EvaluateParallel(JobHandle inputDeps, float stepTime, float substepTime, int substeps)
+        {
+            inputDeps = UpdateInteractions(inputDeps);
+
+            // evaluate all batches as a chain of dependencies:
+            for (int i = 0; i < batches.Count; ++i)
+            {
+                if (batches[i].enabled)
+                {
+                    inputDeps = batches[i].Evaluate(inputDeps, stepTime, substepTime, substeps);
+                    m_Solver.ScheduleBatchedJobsIfNeeded();
+                }
+            }
+
+            // calculate per-particle lambdas:
+            inputDeps = CalculateLambdas(inputDeps, substepTime);
+
+            // then apply them:
+            for (int i = 0; i < batches.Count; ++i)
+            {
+                if (batches[i].enabled)
+                {
+                    inputDeps = batches[i].Apply(inputDeps, substepTime);
+                    m_Solver.ScheduleBatchedJobsIfNeeded();
+                }
+            }
+
+            return inputDeps;
+        }
+
+        public JobHandle ApplyVelocityCorrections(JobHandle inputDeps, float deltaTime)
+        {
+            eta = new NativeArray<float4>(((BurstSolverImpl)solver).particleCount, Allocator.TempJob);
+
+            for (int i = 0; i < batches.Count; ++i)
+            {
+                if (batches[i].enabled)
+                {
+                    inputDeps = batches[i].CalculateViscosityAndNormals(inputDeps, deltaTime);
+                    m_Solver.ScheduleBatchedJobsIfNeeded();
+                }
+            }
+
+            for (int i = 0; i < batches.Count; ++i)
+            {
+                if (batches[i].enabled)
+                {
+                    inputDeps = batches[i].CalculateVorticity(inputDeps);
+                    m_Solver.ScheduleBatchedJobsIfNeeded();
+                }
+            }
+
+            inputDeps = ApplyVorticityAndAtmosphere(inputDeps, deltaTime);
+            m_Solver.ScheduleBatchedJobsIfNeeded();
+
+            return inputDeps;
+        }
+
+        public JobHandle CalculateAnisotropyLaplacianSmoothing(JobHandle inputDeps)
+        {
+            // if the constraints are deactivated or we need no anisotropy:
+            if (((BurstSolverImpl)solver).abstraction.parameters.maxAnisotropy <= 1)
+                return IdentityAnisotropy(inputDeps);
+
+            smoothPositions = new NativeArray<float4>(((BurstSolverImpl)solver).particleCount, Allocator.TempJob);
+            anisotropies = new NativeArray<float3x3>(((BurstSolverImpl)solver).particleCount, Allocator.TempJob);
+
+            for (int i = 0; i < batches.Count; ++i)
+            {
+                if (batches[i].enabled)
+                {
+                    inputDeps = batches[i].AccumulateSmoothPositions(inputDeps);
+                    m_Solver.ScheduleBatchedJobsIfNeeded();
+                }
+            }
+
+            inputDeps = AverageSmoothPositions(inputDeps);
+
+            for (int i = 0; i < batches.Count; ++i)
+            {
+                if (batches[i].enabled)
+                {
+                    inputDeps = batches[i].AccumulateAnisotropy(inputDeps);
+                    m_Solver.ScheduleBatchedJobsIfNeeded();
+                }
+            }
+             
+            return AverageAnisotropy(inputDeps);
+        }
+
+        private JobHandle UpdateInteractions(JobHandle inputDeps)
+        {
+            // clear existing fluid data:
+            var clearData = new ClearFluidDataJob()
+            {
+                fluidParticles = fluidParticles.AsDeferredJobArray(),
+                fluidData = ((BurstSolverImpl)solver).abstraction.fluidData.AsNativeArray<float4>(),
+            };
+
+            inputDeps = clearData.Schedule(fluidParticles.Length, 64, inputDeps);
+
+            // update fluid interactions:
+            var updateInteractions = new UpdateInteractionsJob()
+            {
+                pairs = m_Solver.fluidInteractions,
+                positions = m_Solver.positions,
+                radii = m_Solver.smoothingRadii,
+                densityKernel = new Poly6Kernel(((BurstSolverImpl)solver).abstraction.parameters.mode == Oni.SolverParameters.Mode.Mode2D),
+                gradientKernel = new SpikyKernel(((BurstSolverImpl)solver).abstraction.parameters.mode == Oni.SolverParameters.Mode.Mode2D),
+            };
+
+            return updateInteractions.Schedule(((BurstSolverImpl)solver).fluidInteractions.Length, 64, inputDeps);
+        }
+
+        private JobHandle CalculateLambdas(JobHandle inputDeps, float deltaTime)
+        {
+            // calculate lagrange multipliers:
+            var calculateLambdas = new CalculateLambdasJob()
+            {
+                fluidParticles = fluidParticles.AsDeferredJobArray(),
+                invMasses = m_Solver.invMasses,
+                radii = m_Solver.smoothingRadii,
+                restDensities = m_Solver.restDensities,
+                surfaceTension = m_Solver.surfaceTension,
+                densityKernel = new Poly6Kernel(m_Solver.abstraction.parameters.mode == Oni.SolverParameters.Mode.Mode2D),
+                gradientKernel = new SpikyKernel(m_Solver.abstraction.parameters.mode == Oni.SolverParameters.Mode.Mode2D),
+                normals = m_Solver.normals,
+                vorticity = m_Solver.vorticities,
+                fluidData = m_Solver.fluidData
+            };
+
+            return calculateLambdas.Schedule(fluidParticles.Length,64,inputDeps);
+        }
+
+        private JobHandle ApplyVorticityAndAtmosphere(JobHandle inputDeps, float deltaTime)
+        {
+            // calculate lagrange multipliers:
+            var conf = new ApplyVorticityConfinementAndAtmosphere()
+            {
+                fluidParticles = fluidParticles.AsDeferredJobArray(),
+                wind = m_Solver.wind,
+                vorticities = m_Solver.vorticities,
+                eta = eta,
+                atmosphericDrag = m_Solver.athmosphericDrag,
+                atmosphericPressure = m_Solver.athmosphericPressure,
+                vorticityConfinement = m_Solver.vortConfinement,
+                restDensities = m_Solver.restDensities,
+                normals = m_Solver.normals,
+                fluidData = m_Solver.fluidData,
+                velocities = m_Solver.velocities,
+                dt = deltaTime
+            };
+
+            return conf.Schedule(fluidParticles.Length, 64, inputDeps);
+        }
+
+        private JobHandle IdentityAnisotropy(JobHandle inputDeps)
+        {
+            var idAnisotropy = new IdentityAnisotropyJob()
+            {
+                fluidParticles = fluidParticles.AsDeferredJobArray(),
+                principalAxes = m_Solver.anisotropies,
+                radii = m_Solver.principalRadii
+            };
+
+            return idAnisotropy.Schedule(fluidParticles.Length, 64, inputDeps);
+        }
+
+        private JobHandle AverageSmoothPositions(JobHandle inputDeps)
+        {
+            var average = new AverageSmoothPositionsJob()
+            {
+                fluidParticles = fluidParticles.AsDeferredJobArray(),
+                renderablePositions = m_Solver.renderablePositions,
+                smoothPositions = smoothPositions
+            };
+
+            return average.Schedule(fluidParticles.Length, 64, inputDeps);
+        }
+
+        private JobHandle AverageAnisotropy(JobHandle inputDeps)
+        {
+            var average = new AverageAnisotropyJob()
+            {
+                fluidParticles = fluidParticles.AsDeferredJobArray(),
+                renderablePositions = m_Solver.renderablePositions,
+                smoothPositions = smoothPositions,
+                principalRadii = m_Solver.principalRadii,
+                anisotropies = anisotropies,
+                maxAnisotropy = m_Solver.abstraction.parameters.maxAnisotropy,
+                principalAxes = m_Solver.anisotropies
+            };
+
+            return average.Schedule(fluidParticles.Length, 64, inputDeps);
+        }
+
+        [BurstCompile]
+        public struct ClearFluidDataJob : IJobParallelFor
+        {
+            [ReadOnly] public NativeArray<int> fluidParticles;
+            [NativeDisableContainerSafetyRestriction][NativeDisableParallelForRestriction] public NativeArray<float4> fluidData;
+
+            public void Execute(int i)
+            {
+                fluidData[fluidParticles[i]] = float4.zero;
+            }
+        }
+
+        [BurstCompile]
+        public struct UpdateInteractionsJob : IJobParallelFor
+        {
+            [ReadOnly] public NativeArray<float4> positions;
+            [ReadOnly] public NativeArray<float> radii;
+            [ReadOnly] public Poly6Kernel densityKernel;
+            [ReadOnly] public SpikyKernel gradientKernel;
+
+            [NativeDisableContainerSafetyRestriction][NativeDisableParallelForRestriction] public NativeArray<FluidInteraction> pairs;
+
+            [ReadOnly] public BatchData batchData;
+
+            public void Execute(int i)
+            {
+                var pair = pairs[i];
+
+                // calculate normalized gradient vector:
+                pair.gradient = (positions[pair.particleA] - positions[pair.particleB]);
+                float distance = math.length(pair.gradient);
+                pair.gradient /= distance + math.FLT_MIN_NORMAL;
+
+                // calculate and store average density and gradient kernels:
+                pair.avgKernel = (densityKernel.W(distance, radii[pair.particleA]) +
+                                  densityKernel.W(distance, radii[pair.particleB])) * 0.5f;
+
+                pair.avgGradient = (gradientKernel.W(distance, radii[pair.particleA]) +
+                                    gradientKernel.W(distance, radii[pair.particleB])) * 0.5f;
+
+                pairs[i] = pair;
+            }
+        }
+
+        [BurstCompile]
+        public struct CalculateLambdasJob : IJobParallelFor
+        {
+            [ReadOnly] public NativeArray<int> fluidParticles;
+            [ReadOnly] public NativeArray<float> invMasses;
+            [ReadOnly] public NativeArray<float> radii;
+            [ReadOnly] public NativeArray<float> restDensities;
+            [ReadOnly] public NativeArray<float> surfaceTension;
+            [ReadOnly] public Poly6Kernel densityKernel;
+            [ReadOnly] public SpikyKernel gradientKernel; 
+
+            [NativeDisableContainerSafetyRestriction][NativeDisableParallelForRestriction] public NativeArray<float4> normals;
+            [NativeDisableContainerSafetyRestriction][NativeDisableParallelForRestriction] public NativeArray<float4> vorticity;
+            [NativeDisableContainerSafetyRestriction][NativeDisableParallelForRestriction] public NativeArray<float4> fluidData;
+
+            public void Execute(int p)
+            {
+                int i = fluidParticles[p];
+
+                normals[i] = float4.zero;
+                vorticity[i] = float4.zero;
+
+                float4 data = fluidData[i];
+
+                float grad = gradientKernel.W(0, radii[i]) / invMasses[i] / restDensities[i];
+
+                // self particle contribution to density and gradient:
+                data += new float4(densityKernel.W(0, radii[i]), 0, grad, grad * grad + data[2] * data[2]);
+
+                // weight by mass:
+                data[0] /= invMasses[i];
+
+                // evaluate density constraint (clamp pressure):
+                float constraint = math.max(-0.5f * surfaceTension[i], data[0] / restDensities[i] - 1);
+
+                // calculate lambda:
+                data[1] = -constraint / (invMasses[i] * data[3] + math.FLT_MIN_NORMAL);
+
+                fluidData[i] = data;
+            }
+        }
+
+        [BurstCompile]
+        public struct ApplyVorticityConfinementAndAtmosphere : IJobParallelFor
+        {
+            [ReadOnly] public NativeArray<int> fluidParticles;
+            [ReadOnly] public NativeArray<float4> wind;
+            [ReadOnly] public NativeArray<float4> vorticities;
+            [ReadOnly] public NativeArray<float> atmosphericDrag;
+            [ReadOnly] public NativeArray<float> atmosphericPressure;
+            [ReadOnly] public NativeArray<float> vorticityConfinement;
+            [ReadOnly] public NativeArray<float> restDensities;
+            [ReadOnly] public NativeArray<float4> normals;
+            [ReadOnly] public NativeArray<float4> fluidData;
+
+            [DeallocateOnJobCompletion] [ReadOnly] public NativeArray<float4> eta;
+
+            [NativeDisableContainerSafetyRestriction][NativeDisableParallelForRestriction] public NativeArray<float4> velocities;
+
+            [ReadOnly] public float dt;
+
+            public void Execute(int p)
+            {
+                int i = fluidParticles[p];
+
+                //atmospheric drag:
+                float4 velocityDiff = velocities[i] - wind[i];
+
+                // particles near the surface should experience drag:
+                velocities[i] -= atmosphericDrag[i] * velocityDiff * math.max(0, 1 - fluidData[i][0] / restDensities[i]) * dt;
+
+                // ambient pressure:
+                velocities[i] += atmosphericPressure[i] * normals[i] * dt;
+
+                // apply vorticity confinement:
+                velocities[i] += new float4(math.cross(math.normalizesafe(eta[i]).xyz,vorticities[i].xyz), 0) * vorticityConfinement[i] * dt;
+            }
+        }
+
+        [BurstCompile]
+        public struct IdentityAnisotropyJob : IJobParallelFor
+        {
+            [ReadOnly] public NativeArray<int> fluidParticles;
+            [ReadOnly] public NativeArray<float4> radii;
+
+            [NativeDisableContainerSafetyRestriction][NativeDisableParallelForRestriction] public NativeArray<float4> principalAxes;
+
+            public void Execute(int p)
+            {
+                int i = fluidParticles[p];
+
+                // align the principal axes of the particle with the solver axes:
+                principalAxes[i * 3]     = new float4(1,0,0,radii[i].x);
+                principalAxes[i * 3 + 1] = new float4(0,1,0,radii[i].x);
+                principalAxes[i * 3 + 2] = new float4(0,0,1,radii[i].x);
+            }
+        }
+
+        [BurstCompile]
+        public struct AverageSmoothPositionsJob : IJobParallelFor
+        {
+            [ReadOnly] public NativeArray<int> fluidParticles;
+            [ReadOnly] public NativeArray<float4> renderablePositions;
+
+            [NativeDisableContainerSafetyRestriction][NativeDisableParallelForRestriction] public NativeArray<float4> smoothPositions;
+
+            public void Execute(int p)
+            {
+                int i = fluidParticles[p];
+
+                if (smoothPositions[i].w > 0)
+                    smoothPositions[i] /= smoothPositions[i].w;
+                else
+                    smoothPositions[i] = renderablePositions[i];
+            }
+        }
+
+        [BurstCompile]
+        public struct AverageAnisotropyJob : IJobParallelFor
+        {
+            [ReadOnly] public NativeArray<int> fluidParticles;
+            [ReadOnly] public NativeArray<float4> principalRadii;
+            [ReadOnly] public float maxAnisotropy;
+
+            [ReadOnly]
+            [DeallocateOnJobCompletion]
+            public NativeArray<float4> smoothPositions;
+
+            [ReadOnly]
+            [DeallocateOnJobCompletion]
+            public NativeArray<float3x3> anisotropies;
+
+            [NativeDisableContainerSafetyRestriction][NativeDisableParallelForRestriction] public NativeArray<float4> renderablePositions;
+            [NativeDisableContainerSafetyRestriction][NativeDisableParallelForRestriction] public NativeArray<float4> principalAxes;
+
+            public void Execute(int p)
+            {
+                int i = fluidParticles[p];
+
+                if (smoothPositions[i].w > 0 && (anisotropies[i].c0[0] + anisotropies[i].c1[1] + anisotropies[i].c2[2]) > 0.01f)
+                {
+                    float3 singularValues;
+                    float3x3 u;
+                    BurstMath.EigenSolve(anisotropies[i] / smoothPositions[i].w, out singularValues, out u);
+
+                    float max = singularValues[0];
+                    float3 s = math.max(singularValues,new float3(max / maxAnisotropy)) / max * principalRadii[i].x;
+
+                    principalAxes[i * 3]     = new float4(u.c0, s.x);
+                    principalAxes[i * 3 + 1] = new float4(u.c1, s.y);
+                    principalAxes[i * 3 + 2] = new float4(u.c2, s.z);
+                }
+                else
+                {
+                    float radius = principalRadii[i].x / maxAnisotropy;
+                    principalAxes[i * 3]     = new float4(1, 0, 0, radius);
+                    principalAxes[i * 3 + 1] = new float4(0, 1, 0, radius);
+                    principalAxes[i * 3 + 2] = new float4(0, 0, 1, radius);
+                }
+
+                renderablePositions[i] = smoothPositions[i];
+            }
+        }
+    }
+}
+#endif

Assets/Obi/Scripts/Common/Backends/Burst/Constraints/Density/BurstDensityConstraints.cs.meta

@@ -0,0 +1,11 @@
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+guid: df96ac4db14c846ea99a6ebc5771098f
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/Obi/Scripts/Common/Backends/Burst/Constraints/Density/BurstDensityConstraintsBatch.cs

@@ -0,0 +1,371 @@
+#if (OBI_BURST && OBI_MATHEMATICS && OBI_COLLECTIONS)
+using UnityEngine;
+using Unity.Jobs;
+using Unity.Collections;
+using Unity.Collections.LowLevel.Unsafe;
+using Unity.Mathematics;
+using Unity.Burst;
+using System.Collections;
+
+namespace Obi
+{
+    public class BurstDensityConstraintsBatch : BurstConstraintsBatchImpl, IDensityConstraintsBatchImpl
+    {
+        public BatchData batchData;
+
+        public BurstDensityConstraintsBatch(BurstDensityConstraints constraints)
+        {
+            m_Constraints = constraints;
+            m_ConstraintType = Oni.ConstraintType.Density;
+        }
+
+        public override JobHandle Initialize(JobHandle inputDeps, float substepTime)
+        {
+            return inputDeps;
+        }
+
+        public override JobHandle Evaluate(JobHandle inputDeps, float stepTime, float substepTime, int substeps)
+        {
+
+            // update densities and gradients:
+            var updateDensities = new UpdateDensitiesJob()
+            {
+                pairs = ((BurstSolverImpl)constraints.solver).fluidInteractions,
+                positions = solverImplementation.positions,
+                invMasses = solverImplementation.invMasses,
+                restDensities = solverImplementation.restDensities,
+                diffusion = solverImplementation.diffusion,
+                userData = solverImplementation.userData,
+                fluidData = solverImplementation.fluidData,
+                batchData = batchData,
+                dt = substepTime
+            };
+
+            int batchCount = batchData.isLast ? batchData.workItemCount : 1;
+            return updateDensities.Schedule(batchData.workItemCount, batchCount, inputDeps);
+        }
+
+        public override JobHandle Apply(JobHandle inputDeps, float substepTime)
+        {
+            var parameters = solverAbstraction.GetConstraintParameters(m_ConstraintType);
+
+            // update densities and gradients:
+            var apply = new ApplyDensityConstraintsJob()
+            {
+                invMasses = solverImplementation.invMasses,
+                radii = solverImplementation.smoothingRadii,
+                restDensities = solverImplementation.restDensities,
+                surfaceTension = solverImplementation.surfaceTension,
+                pairs = ((BurstSolverImpl)constraints.solver).fluidInteractions,
+                densityKernel = new Poly6Kernel(solverAbstraction.parameters.mode == Oni.SolverParameters.Mode.Mode2D),
+                positions = solverImplementation.positions,
+                fluidData = solverImplementation.fluidData,
+                batchData = batchData,
+                sorFactor = parameters.SORFactor
+            };
+
+            int batchCount = batchData.isLast ? batchData.workItemCount : 1;
+            return apply.Schedule(batchData.workItemCount, batchCount, inputDeps);
+        }
+
+        public JobHandle CalculateViscosityAndNormals(JobHandle inputDeps, float deltaTime)
+        {
+            var viscosity = new NormalsViscosityAndVorticityJob()
+            {
+                positions = solverImplementation.positions,
+                invMasses = solverImplementation.invMasses,
+                radii = solverImplementation.smoothingRadii,
+                restDensities = solverImplementation.restDensities,
+                viscosities = solverImplementation.viscosities,
+                fluidData = solverImplementation.fluidData,
+                pairs = ((BurstSolverImpl)constraints.solver).fluidInteractions,
+                velocities = solverImplementation.velocities,
+                vorticities = solverImplementation.vorticities,
+                normals = solverImplementation.normals,
+                batchData = batchData
+            };
+
+            int batchCount = batchData.isLast ? batchData.workItemCount : 1;
+            return viscosity.Schedule(batchData.workItemCount, batchCount, inputDeps);
+        }
+
+        public JobHandle CalculateVorticity(JobHandle inputDeps)
+        {
+            var eta = new CalculateVorticityEta()
+            {
+                invMasses = solverImplementation.invMasses,
+                restDensities = solverImplementation.restDensities,
+                pairs = ((BurstSolverImpl)constraints.solver).fluidInteractions,
+                vorticities = solverImplementation.vorticities,
+                eta = ((BurstDensityConstraints)this.constraints).eta,
+                batchData = batchData
+            };
+
+            int batchCount = batchData.isLast ? batchData.workItemCount : 1;
+            return eta.Schedule(batchData.workItemCount, batchCount, inputDeps);
+        }
+
+        public JobHandle AccumulateSmoothPositions(JobHandle inputDeps)
+        {
+            var accumulateSmooth = new AccumulateSmoothPositionsJob()
+            {
+                renderablePositions = solverImplementation.renderablePositions,
+                smoothPositions = ((BurstDensityConstraints)this.constraints).smoothPositions,
+                radii = solverImplementation.smoothingRadii,
+                densityKernel = new Poly6Kernel(solverAbstraction.parameters.mode == Oni.SolverParameters.Mode.Mode2D),
+                pairs = ((BurstSolverImpl)constraints.solver).fluidInteractions,
+                batchData = batchData
+            };
+
+            int batchCount = batchData.isLast ? batchData.workItemCount : 1;
+            return accumulateSmooth.Schedule(batchData.workItemCount, batchCount, inputDeps);
+        }
+
+        public JobHandle AccumulateAnisotropy(JobHandle inputDeps)
+        {
+            var accumulateAnisotropy = new AccumulateAnisotropyJob()
+            {
+                renderablePositions = solverImplementation.renderablePositions,
+                smoothPositions = ((BurstDensityConstraints)this.constraints).smoothPositions,
+                anisotropies = ((BurstDensityConstraints)this.constraints).anisotropies,
+                pairs = ((BurstSolverImpl)constraints.solver).fluidInteractions,
+                batchData = batchData
+            };
+
+            int batchCount = batchData.isLast ? batchData.workItemCount : 1;
+            return accumulateAnisotropy.Schedule(batchData.workItemCount, batchCount, inputDeps);
+        }
+
+        [BurstCompile]
+        public struct UpdateDensitiesJob : IJobParallelFor
+        {
+            [ReadOnly] public NativeArray<float4> positions;
+            [ReadOnly] public NativeArray<float> invMasses;
+            [ReadOnly] public NativeArray<float> restDensities;
+            [ReadOnly] public NativeArray<float> diffusion;
+            [ReadOnly] public NativeArray<FluidInteraction> pairs;
+
+            [NativeDisableContainerSafetyRestriction][NativeDisableParallelForRestriction] public NativeArray<float4> userData;
+            [NativeDisableContainerSafetyRestriction][NativeDisableParallelForRestriction] public NativeArray<float4> fluidData;
+
+            [ReadOnly] public BatchData batchData;
+
+            [ReadOnly] public float dt;
+
+            public void Execute(int workItemIndex)
+            {
+                int start, end;
+                batchData.GetConstraintRange(workItemIndex, out start, out end);
+
+                for (int i = start; i < end; ++i)
+                {
+                    var pair = pairs[i];
+
+                    float restVolumeA = 1.0f / invMasses[pair.particleA] / restDensities[pair.particleA];
+                    float restVolumeB = 1.0f / invMasses[pair.particleB] / restDensities[pair.particleB];
+
+                    float gradA = restVolumeB * pair.avgGradient;
+                    float gradB = restVolumeA * pair.avgGradient;
+
+                    float vA = restVolumeB / restVolumeA;
+                    float vB = restVolumeA / restVolumeB;
+
+                    // accumulate pbf data (density, gradients):
+                    fluidData[pair.particleA] += new float4(vA * pair.avgKernel, 0, gradA, gradA * gradA);
+                    fluidData[pair.particleB] += new float4(vB * pair.avgKernel, 0, gradB, gradB * gradB);
+
+                    // property diffusion:
+                    float diffusionSpeed = (diffusion[pair.particleA] + diffusion[pair.particleB]) * pair.avgKernel * dt;
+                    float4 userDelta = (userData[pair.particleB] - userData[pair.particleA]) * diffusionSpeed;
+                    userData[pair.particleA] += vA * userDelta;
+                    userData[pair.particleB] -= vB * userDelta;
+                }
+            }
+        }
+
+        [BurstCompile]
+        public struct ApplyDensityConstraintsJob : IJobParallelFor
+        {
+            [ReadOnly] public NativeArray<float> invMasses;
+            [ReadOnly] public NativeArray<float> radii;
+            [ReadOnly] public NativeArray<float> restDensities;
+            [ReadOnly] public NativeArray<float> surfaceTension;
+            [ReadOnly] public NativeArray<FluidInteraction> pairs;
+            [ReadOnly] public Poly6Kernel densityKernel;
+
+            [NativeDisableContainerSafetyRestriction][NativeDisableParallelForRestriction] public NativeArray<float4> positions;
+            [NativeDisableContainerSafetyRestriction][NativeDisableParallelForRestriction] public NativeArray<float4> fluidData;
+
+            [ReadOnly] public BatchData batchData;
+            [ReadOnly] public float sorFactor;
+
+            public void Execute(int workItemIndex)
+            {
+                int start, end;
+                batchData.GetConstraintRange(workItemIndex, out start, out end);
+
+                for (int i = start; i < end; ++i)
+                {
+                    var pair = pairs[i];
+
+                    float restVolumeA = 1.0f / invMasses[pair.particleA] / restDensities[pair.particleA];
+                    float restVolumeB = 1.0f / invMasses[pair.particleB] / restDensities[pair.particleB];
+
+                    // calculate tensile instability correction factor:
+                    float wAvg = pair.avgKernel / ((densityKernel.W(0, radii[pair.particleA]) + densityKernel.W(0, radii[pair.particleB])) * 0.5f);
+                    float scorrA = -(0.001f + 0.2f * surfaceTension[pair.particleA]) * wAvg / (invMasses[pair.particleA] * fluidData[pair.particleA][3]);
+                    float scorrB = -(0.001f + 0.2f * surfaceTension[pair.particleB]) * wAvg / (invMasses[pair.particleB] * fluidData[pair.particleB][3]);
+
+                    // calculate position delta:
+                    float4 delta = pair.gradient * pair.avgGradient * ((fluidData[pair.particleA][1] + scorrA) * restVolumeB + (fluidData[pair.particleB][1] + scorrB) * restVolumeA) * sorFactor;
+                    positions[pair.particleA] += delta * invMasses[pair.particleA];
+                    positions[pair.particleB] -= delta * invMasses[pair.particleB];
+                }
+            }
+        }
+
+        [BurstCompile]
+        public struct NormalsViscosityAndVorticityJob : IJobParallelFor
+        {
+            [ReadOnly] public NativeArray<float4> positions;
+            [ReadOnly] public NativeArray<float> invMasses;
+            [ReadOnly] public NativeArray<float> radii;
+            [ReadOnly] public NativeArray<float> restDensities;
+            [ReadOnly] public NativeArray<float> viscosities;
+            [ReadOnly] public NativeArray<float4> fluidData;
+            [ReadOnly] public NativeArray<FluidInteraction> pairs;
+
+            [NativeDisableContainerSafetyRestriction][NativeDisableParallelForRestriction] public NativeArray<float4> velocities;
+            [NativeDisableContainerSafetyRestriction][NativeDisableParallelForRestriction] public NativeArray<float4> vorticities;
+            [NativeDisableContainerSafetyRestriction][NativeDisableParallelForRestriction] public NativeArray<float4> normals;
+
+            [ReadOnly] public BatchData batchData;
+
+            public void Execute(int workItemIndex)
+            {
+                int start, end;
+                batchData.GetConstraintRange(workItemIndex, out start, out end);
+
+                for (int i = start; i < end; ++i)
+                {
+                    var pair = pairs[i];
+
+                    float restVolumeA = 1.0f / invMasses[pair.particleA] / restDensities[pair.particleA];
+                    float restVolumeB = 1.0f / invMasses[pair.particleB] / restDensities[pair.particleB];
+
+                    // XSPH viscosity:
+                    float viscosityCoeff = math.min(viscosities[pair.particleA], viscosities[pair.particleB]);
+                    float4 relVelocity = velocities[pair.particleB] - velocities[pair.particleA];
+                    float4 viscosity = viscosityCoeff * relVelocity * pair.avgKernel;
+                    velocities[pair.particleA] += viscosity * restVolumeB;
+                    velocities[pair.particleB] -= viscosity * restVolumeA;
+
+                    // calculate vorticity:
+                    float4 vgrad = pair.gradient * pair.avgGradient;
+                    float4 vorticity = new float4(math.cross(relVelocity.xyz,vgrad.xyz),0);
+                    vorticities[pair.particleA] += vorticity * restVolumeB;
+                    vorticities[pair.particleB] += vorticity * restVolumeA;
+
+                    // calculate color field  normal:
+                    float radius = (radii[pair.particleA] + radii[pair.particleB]) * 0.5f;
+                    normals[pair.particleA] += vgrad * radius / invMasses[pair.particleB] / fluidData[pair.particleB][0];
+                    normals[pair.particleB] -= vgrad * radius / invMasses[pair.particleA] / fluidData[pair.particleA][0];
+                }
+            }
+        }
+
+        [BurstCompile]
+        public struct CalculateVorticityEta : IJobParallelFor
+        {
+            [ReadOnly] public NativeArray<float4> vorticities;
+            [ReadOnly] public NativeArray<float> invMasses;
+            [ReadOnly] public NativeArray<float> restDensities;
+
+            [NativeDisableContainerSafetyRestriction][NativeDisableParallelForRestriction] public NativeArray<FluidInteraction> pairs;
+            [NativeDisableContainerSafetyRestriction][NativeDisableParallelForRestriction] public NativeArray<float4> eta;
+
+            [ReadOnly] public BatchData batchData;
+
+            public void Execute(int workItemIndex)
+            {
+                int start, end;
+                batchData.GetConstraintRange(workItemIndex, out start, out end);
+
+                for (int i = start; i < end; ++i)
+                {
+                    var pair = pairs[i];
+
+                    float4 vgrad = pair.gradient * pair.avgGradient;
+                    eta[pair.particleA] += math.length(vorticities[pair.particleA]) * vgrad / invMasses[pair.particleB] / restDensities[pair.particleB];
+                    eta[pair.particleB] -= math.length(vorticities[pair.particleB]) * vgrad / invMasses[pair.particleA] / restDensities[pair.particleA];
+                }
+            }
+        }
+
+        [BurstCompile]
+        public struct AccumulateSmoothPositionsJob : IJobParallelFor
+        {
+            [ReadOnly] public NativeArray<float4> renderablePositions;
+            [ReadOnly] public NativeArray<float> radii;
+            [ReadOnly] public Poly6Kernel densityKernel;
+
+            [NativeDisableContainerSafetyRestriction][NativeDisableParallelForRestriction] public NativeArray<float4> smoothPositions;
+            [NativeDisableContainerSafetyRestriction][NativeDisableParallelForRestriction] public NativeArray<FluidInteraction> pairs;
+
+            [ReadOnly] public BatchData batchData;
+
+            public void Execute(int workItemIndex)
+            {
+                int start, end;
+                batchData.GetConstraintRange(workItemIndex, out start, out end);
+
+                for (int i = start; i < end; ++i)
+                {
+                    var pair = pairs[i];
+
+                    float4 gradient = (renderablePositions[pair.particleA] - renderablePositions[pair.particleB]);
+                    float distance = math.length(gradient);
+
+                    pair.avgKernel = (densityKernel.W(distance, radii[pair.particleA]) +
+                                      densityKernel.W(distance, radii[pair.particleB])) * 0.5f;
+
+                    smoothPositions[pair.particleA] += new float4(renderablePositions[pair.particleB].xyz,1) * pair.avgKernel;
+                    smoothPositions[pair.particleB] += new float4(renderablePositions[pair.particleA].xyz,1) * pair.avgKernel;
+
+                    pairs[i] = pair;
+                }
+            }
+        }
+
+        [BurstCompile]
+        public struct AccumulateAnisotropyJob : IJobParallelFor
+        {
+            [ReadOnly] public NativeArray<float4> renderablePositions;
+            [ReadOnly] public NativeArray<float4> smoothPositions;
+            [ReadOnly] public NativeArray<FluidInteraction> pairs;
+
+            [NativeDisableContainerSafetyRestriction][NativeDisableParallelForRestriction] public NativeArray<float3x3> anisotropies;
+
+            [ReadOnly] public BatchData batchData;
+
+            public void Execute(int workItemIndex)
+            {
+                int start, end;
+                batchData.GetConstraintRange(workItemIndex, out start, out end);
+
+                for (int i = start; i < end; ++i)
+                {
+                    var pair = pairs[i];
+
+                    float4 distanceA = renderablePositions[pair.particleB] - smoothPositions[pair.particleA];
+                    float4 distanceB = renderablePositions[pair.particleA] - smoothPositions[pair.particleB];
+
+                    anisotropies[pair.particleA] += BurstMath.multrnsp(distanceA,distanceA) * pair.avgKernel;
+                    anisotropies[pair.particleB] += BurstMath.multrnsp(distanceB,distanceB) * pair.avgKernel;
+                }
+            }
+        }
+
+    }
+}
+#endif

Assets/Obi/Scripts/Common/Backends/Burst/Constraints/Density/BurstDensityConstraintsBatch.cs.meta

@@ -0,0 +1,11 @@
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Assets/Obi/Scripts/Common/Backends/Burst/Constraints/Density/Kernels.meta

@@ -0,0 +1,8 @@
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Assets/Obi/Scripts/Common/Backends/Burst/Constraints/Density/Kernels/Poly6Kernel.cs

@@ -0,0 +1,36 @@
+#if (OBI_BURST && OBI_MATHEMATICS && OBI_COLLECTIONS)
+using System;
+using Unity.Mathematics;
+
+namespace Obi
+{
+    public struct Poly6Kernel
+    {
+        public float norm;
+        public bool norm2D;
+
+        public Poly6Kernel(bool norm2D)
+        {
+            this.norm2D = norm2D;
+            if (norm2D)
+                norm = 4.0f / math.PI;
+            else
+                norm = 315.0f / (64.0f * math.PI);
+        }
+
+        public float W(float r, float h)
+        {
+            float h2 = h * h;
+            float h4 = h2 * h2;
+            float h8 = h4 * h4;
+
+            float rl = math.min(r, h);
+            float hr = h2 - rl * rl;
+
+            if (norm2D)
+                return norm / h8 * hr * hr * hr;
+            return norm / (h8 * h) * hr * hr * hr;
+        }
+    }
+}
+#endif

Assets/Obi/Scripts/Common/Backends/Burst/Constraints/Density/Kernels/Poly6Kernel.cs.meta

@@ -0,0 +1,11 @@
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Assets/Obi/Scripts/Common/Backends/Burst/Constraints/Density/Kernels/SpikyKernel.cs

@@ -0,0 +1,35 @@
+#if (OBI_BURST && OBI_MATHEMATICS && OBI_COLLECTIONS)
+using System;
+using Unity.Mathematics;
+
+namespace Obi
+{
+    public struct SpikyKernel
+    {
+        public float norm;
+        public bool norm2D;
+
+        public SpikyKernel(bool norm2D)
+        {
+            this.norm2D = norm2D;
+            if (norm2D)
+                norm = -30.0f / math.PI;
+            else
+                norm = -45.0f / math.PI;
+        }
+
+        public float W(float r, float h)
+        {
+            float h2 = h * h;
+            float h4 = h2 * h2;
+
+            float rl = math.min(r, h);
+            float hr = h - rl;
+
+            if (norm2D)
+                return norm / (h4 * h) * hr * hr;
+            return norm / (h4 * h2) * hr * hr;
+        }
+    }
+}
+#endif

Assets/Obi/Scripts/Common/Backends/Burst/Constraints/Density/Kernels/SpikyKernel.cs.meta

@@ -0,0 +1,11 @@
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Assets/Obi/Scripts/Common/Backends/Burst/Constraints/Distance.meta

@@ -0,0 +1,8 @@
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Assets/Obi/Scripts/Common/Backends/Burst/Constraints/Distance/BurstDistanceConstraints.cs

@@ -0,0 +1,26 @@
+#if (OBI_BURST && OBI_MATHEMATICS && OBI_COLLECTIONS)
+using System;
+
+namespace Obi
+{
+    public class BurstDistanceConstraints : BurstConstraintsImpl<BurstDistanceConstraintsBatch>
+    {
+        public BurstDistanceConstraints(BurstSolverImpl solver) : base(solver, Oni.ConstraintType.Distance)
+        {
+        }
+
+        public override IConstraintsBatchImpl CreateConstraintsBatch()
+        {
+            var dataBatch = new BurstDistanceConstraintsBatch(this);
+            batches.Add(dataBatch);
+            return dataBatch;
+        }
+
+        public override void RemoveBatch(IConstraintsBatchImpl batch)
+        {
+            batches.Remove(batch as BurstDistanceConstraintsBatch);
+            batch.Destroy();
+        }
+    }
+}
+#endif

Assets/Obi/Scripts/Common/Backends/Burst/Constraints/Distance/BurstDistanceConstraints.cs.meta

@@ -0,0 +1,11 @@
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Assets/Obi/Scripts/Common/Backends/Burst/Constraints/Distance/BurstDistanceConstraintsBatch.cs

@@ -0,0 +1,146 @@
+#if (OBI_BURST && OBI_MATHEMATICS && OBI_COLLECTIONS)
+using UnityEngine;
+using Unity.Jobs;
+using Unity.Collections;
+using Unity.Collections.LowLevel.Unsafe;
+using Unity.Mathematics;
+using Unity.Burst;
+using System.Collections;
+
+namespace Obi
+{
+    public class BurstDistanceConstraintsBatch : BurstConstraintsBatchImpl, IDistanceConstraintsBatchImpl
+    {
+        private NativeArray<float> restLengths;
+        private NativeArray<float2> stiffnesses;
+
+        DistanceConstraintsBatchJob projectConstraints;
+        ApplyDistanceConstraintsBatchJob applyConstraints;
+
+        public BurstDistanceConstraintsBatch(BurstDistanceConstraints constraints)
+        {
+            m_Constraints = constraints;
+            m_ConstraintType = Oni.ConstraintType.Distance;
+        }
+
+        public void SetDistanceConstraints(ObiNativeIntList particleIndices, ObiNativeFloatList restLengths, ObiNativeVector2List stiffnesses, ObiNativeFloatList lambdas, int count)
+        {
+            this.particleIndices = particleIndices.AsNativeArray<int>();
+            this.restLengths = restLengths.AsNativeArray<float>();
+            this.stiffnesses = stiffnesses.AsNativeArray<float2>();
+            this.lambdas = lambdas.AsNativeArray<float>();
+            m_ConstraintCount = count;
+
+            projectConstraints.particleIndices = this.particleIndices;
+            projectConstraints.restLengths = this.restLengths;
+            projectConstraints.stiffnesses = this.stiffnesses;
+            projectConstraints.lambdas = this.lambdas;
+
+            applyConstraints.particleIndices = this.particleIndices;
+        }
+
+        public override JobHandle Evaluate(JobHandle inputDeps, float stepTime, float substepTime, int substeps)
+        {
+            projectConstraints.positions = solverImplementation.positions;
+            projectConstraints.invMasses = solverImplementation.invMasses;
+            projectConstraints.deltas = solverImplementation.positionDeltas;
+            projectConstraints.counts = solverImplementation.positionConstraintCounts;
+            projectConstraints.deltaTimeSqr = substepTime * substepTime;
+
+            return projectConstraints.Schedule(m_ConstraintCount, 32, inputDeps);
+        }
+
+        public override JobHandle Apply(JobHandle inputDeps, float substepTime)
+        {
+            var parameters = solverAbstraction.GetConstraintParameters(m_ConstraintType);
+
+            applyConstraints.positions = solverImplementation.positions;
+            applyConstraints.deltas = solverImplementation.positionDeltas;
+            applyConstraints.counts = solverImplementation.positionConstraintCounts;
+            applyConstraints.sorFactor = parameters.SORFactor;
+
+            return applyConstraints.Schedule(m_ConstraintCount, 64, inputDeps);
+        }
+
+        [BurstCompile]
+        public struct DistanceConstraintsBatchJob : IJobParallelFor
+        {
+            [ReadOnly] public NativeArray<int> particleIndices;
+            [ReadOnly] public NativeArray<float> restLengths;
+            [ReadOnly] public NativeArray<float2> stiffnesses;
+            public NativeArray<float> lambdas;
+
+            [ReadOnly] public NativeArray<float4> positions;
+            [ReadOnly] public NativeArray<float> invMasses;
+
+            [NativeDisableContainerSafetyRestriction][NativeDisableParallelForRestriction] public NativeArray<float4> deltas;
+            [NativeDisableContainerSafetyRestriction][NativeDisableParallelForRestriction] public NativeArray<int> counts;
+
+            [ReadOnly] public float deltaTimeSqr;
+
+            public void Execute(int i)
+            {
+                int p1 = particleIndices[i * 2];
+                int p2 = particleIndices[i * 2 + 1];
+
+                float w1 = invMasses[p1];
+                float w2 = invMasses[p2];
+
+                // calculate time adjusted compliance
+                float compliance = stiffnesses[i].x / deltaTimeSqr;
+
+                // calculate position and lambda deltas:
+                float4 distance = positions[p1] - positions[p2];
+                float d = math.length(distance);
+
+                // calculate constraint value:
+                float constraint = d - restLengths[i];
+                constraint -= math.max(math.min(constraint, 0), -stiffnesses[i].y);
+
+                // calculate lambda and position deltas:
+                float dlambda = (-constraint - compliance * lambdas[i]) / (w1 + w2 + compliance + BurstMath.epsilon);
+                float4 delta = dlambda * distance / (d + BurstMath.epsilon);
+
+                lambdas[i] += dlambda;
+
+                deltas[p1] += delta * w1;
+                deltas[p2] -= delta * w2;
+
+                counts[p1]++;
+                counts[p2]++;
+            }
+        }
+
+        [BurstCompile]
+        public struct ApplyDistanceConstraintsBatchJob : IJobParallelFor
+        {
+            [ReadOnly] public NativeArray<int> particleIndices;
+            [ReadOnly] public float sorFactor;
+
+            [NativeDisableContainerSafetyRestriction][NativeDisableParallelForRestriction] public NativeArray<float4> positions;
+            [NativeDisableContainerSafetyRestriction][NativeDisableParallelForRestriction] public NativeArray<float4> deltas;
+            [NativeDisableContainerSafetyRestriction][NativeDisableParallelForRestriction] public NativeArray<int> counts;
+
+            public void Execute(int i)
+            {
+                int p1 = particleIndices[i * 2];
+                int p2 = particleIndices[i * 2 + 1];
+
+                if (counts[p1] > 0)
+                {
+                    positions[p1] += deltas[p1] * sorFactor / counts[p1];
+                    deltas[p1] = float4.zero;
+                    counts[p1] = 0;
+                }
+
+                if (counts[p2] > 0)
+                {
+                    positions[p2] += deltas[p2] * sorFactor / counts[p2];
+                    deltas[p2] = float4.zero;
+                    counts[p2] = 0;
+                }
+            }
+        }
+    }
+}
+#endif

Assets/Obi/Scripts/Common/Backends/Burst/Constraints/Distance/BurstDistanceConstraintsBatch.cs.meta

@@ -0,0 +1,11 @@
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Assets/Obi/Scripts/Common/Backends/Burst/Constraints/ParticleCollision.meta

@@ -0,0 +1,8 @@
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Assets/Obi/Scripts/Common/Backends/Burst/Constraints/ParticleCollision/ApplyBatchedCollisionConstraintsBatchJob.cs

@@ -0,0 +1,62 @@
+#if (OBI_BURST && OBI_MATHEMATICS && OBI_COLLECTIONS)
+using UnityEngine;
+using Unity.Jobs;
+using Unity.Collections;
+using Unity.Mathematics;
+using Unity.Burst;
+using System;
+using System.Collections;
+
+namespace Obi
+{
+
+    [BurstCompile]
+    public struct ApplyBatchedCollisionConstraintsBatchJob : IJobParallelFor
+    {
+        [ReadOnly] public NativeArray<BurstContact> contacts;
+
+        [ReadOnly] public NativeArray<int> simplices;
+        [ReadOnly] public SimplexCounts simplexCounts;
+
+        [NativeDisableParallelForRestriction] public NativeArray<float4> positions;
+        [NativeDisableParallelForRestriction] public NativeArray<float4> deltas;
+        [NativeDisableParallelForRestriction] public NativeArray<int> counts;
+
+        [NativeDisableParallelForRestriction] public NativeArray<quaternion> orientations;
+        [NativeDisableParallelForRestriction] public NativeArray<quaternion> orientationDeltas;
+        [NativeDisableParallelForRestriction] public NativeArray<int> orientationCounts;
+
+        [ReadOnly] public Oni.ConstraintParameters constraintParameters;
+        [ReadOnly] public BatchData batchData;
+
+        public void Execute(int workItemIndex)
+        {
+            int start, end;
+            batchData.GetConstraintRange(workItemIndex, out start, out end);
+
+            for (int i = start; i < end; ++i)
+            {
+                int simplexStartA = simplexCounts.GetSimplexStartAndSize(contacts[i].bodyA, out int simplexSizeA);
+                int simplexStartB = simplexCounts.GetSimplexStartAndSize(contacts[i].bodyB, out int simplexSizeB);
+
+                for (int j = 0; j < simplexSizeA; ++j)
+                {
+                    int particleIndex = simplices[simplexStartA + j];
+                    BurstConstraintsBatchImpl.ApplyPositionDelta(particleIndex, constraintParameters.SORFactor, ref positions, ref deltas, ref counts);
+                    BurstConstraintsBatchImpl.ApplyOrientationDelta(particleIndex, constraintParameters.SORFactor, ref orientations, ref orientationDeltas, ref orientationCounts);
+                }
+
+                for (int j = 0; j < simplexSizeB; ++j)
+                {
+                    int particleIndex = simplices[simplexStartB + j];
+                    BurstConstraintsBatchImpl.ApplyPositionDelta(particleIndex, constraintParameters.SORFactor, ref positions, ref deltas, ref counts);
+                    BurstConstraintsBatchImpl.ApplyOrientationDelta(particleIndex, constraintParameters.SORFactor, ref orientations, ref orientationDeltas, ref orientationCounts);
+                }
+
+            }
+            
+        }
+
+    }
+}
+#endif

Assets/Obi/Scripts/Common/Backends/Burst/Constraints/ParticleCollision/ApplyBatchedCollisionConstraintsBatchJob.cs.meta

@@ -0,0 +1,11 @@
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Assets/Obi/Scripts/Common/Backends/Burst/Constraints/ParticleCollision/BurstParticleCollisionConstraints.cs

@@ -0,0 +1,34 @@
+#if (OBI_BURST && OBI_MATHEMATICS && OBI_COLLECTIONS)
+using System;
+using Unity.Jobs;
+
+namespace Obi
+{
+    public class BurstParticleCollisionConstraints : BurstConstraintsImpl<BurstParticleCollisionConstraintsBatch>
+    {
+        public BurstParticleCollisionConstraints(BurstSolverImpl solver) : base(solver, Oni.ConstraintType.ParticleCollision)
+        {
+        }
+
+        public override IConstraintsBatchImpl CreateConstraintsBatch()
+        {
+            var dataBatch = new BurstParticleCollisionConstraintsBatch(this);
+            batches.Add(dataBatch);
+            return dataBatch;
+        }
+
+        public override void RemoveBatch(IConstraintsBatchImpl batch)
+        {
+            batches.Remove(batch as BurstParticleCollisionConstraintsBatch);
+            batch.Destroy();
+        }
+
+        public override int GetConstraintCount()
+        {
+            if (!((BurstSolverImpl)solver).particleContacts.IsCreated)
+                return 0;
+            return ((BurstSolverImpl)solver).particleContacts.Length;
+        }
+    }
+}
+#endif

Assets/Obi/Scripts/Common/Backends/Burst/Constraints/ParticleCollision/BurstParticleCollisionConstraints.cs.meta

@@ -0,0 +1,11 @@
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Assets/Obi/Scripts/Common/Backends/Burst/Constraints/ParticleCollision/BurstParticleCollisionConstraintsBatch.cs

@@ -0,0 +1,335 @@
+#if (OBI_BURST && OBI_MATHEMATICS && OBI_COLLECTIONS)
+using UnityEngine;
+using Unity.Jobs;
+using Unity.Collections;
+using Unity.Collections.LowLevel.Unsafe;
+using Unity.Mathematics;
+using Unity.Burst;
+using System.Collections;
+
+namespace Obi
+{
+    public class BurstParticleCollisionConstraintsBatch : BurstConstraintsBatchImpl, IParticleCollisionConstraintsBatchImpl
+    {
+        public BatchData batchData;
+
+        public BurstParticleCollisionConstraintsBatch(BurstParticleCollisionConstraints constraints)
+        {
+            m_Constraints = constraints;
+            m_ConstraintType = Oni.ConstraintType.ParticleCollision;
+        }
+
+        public BurstParticleCollisionConstraintsBatch(BatchData batchData) : base()
+        {
+            this.batchData = batchData;
+        }
+
+        public override JobHandle Initialize(JobHandle inputDeps, float substepTime)
+        {
+            var updateContacts = new UpdateParticleContactsJob()
+            {
+                prevPositions = solverImplementation.prevPositions,
+                prevOrientations = solverImplementation.prevOrientations,
+                velocities = solverImplementation.velocities,
+                radii = solverImplementation.principalRadii,
+                invMasses = solverImplementation.invMasses,
+                invInertiaTensors = solverImplementation.invInertiaTensors,
+
+                simplices = solverImplementation.simplices,
+                simplexCounts = solverImplementation.simplexCounts,
+
+                particleMaterialIndices = solverImplementation.collisionMaterials,
+                collisionMaterials = ObiColliderWorld.GetInstance().collisionMaterials.AsNativeArray<BurstCollisionMaterial>(),
+
+                contacts = ((BurstSolverImpl)constraints.solver).particleContacts,
+                batchData = batchData
+            };
+
+            int batchCount = batchData.isLast ? batchData.workItemCount : 1;
+            return updateContacts.Schedule(batchData.workItemCount, batchCount, inputDeps);
+        }
+
+        public override JobHandle Evaluate(JobHandle inputDeps, float stepTime, float substepTime, int substeps)
+        {
+            var parameters = solverAbstraction.GetConstraintParameters(m_ConstraintType);
+
+            var projectConstraints = new ParticleCollisionConstraintsBatchJob()
+            {
+                positions = solverImplementation.positions,
+                orientations = solverImplementation.orientations,
+                invMasses = solverImplementation.invMasses,
+                radii = solverImplementation.principalRadii,
+                particleMaterialIndices = solverImplementation.collisionMaterials,
+                collisionMaterials = ObiColliderWorld.GetInstance().collisionMaterials.AsNativeArray<BurstCollisionMaterial>(),
+
+                simplices = solverImplementation.simplices,
+                simplexCounts = solverImplementation.simplexCounts,
+
+                deltas = solverImplementation.positionDeltas,
+                counts = solverImplementation.positionConstraintCounts,
+                contacts = ((BurstSolverImpl)constraints.solver).particleContacts,
+                batchData = batchData,
+
+                constraintParameters = parameters,
+                solverParameters = solverImplementation.abstraction.parameters,
+                gravity = new float4(solverImplementation.abstraction.parameters.gravity, 0),
+                substepTime = substepTime,
+            };
+
+            int batchCount = batchData.isLast ? batchData.workItemCount : 1;
+            return projectConstraints.Schedule(batchData.workItemCount, batchCount, inputDeps);
+        }
+
+        public override JobHandle Apply(JobHandle inputDeps, float substepTime)
+        {
+            var parameters = solverAbstraction.GetConstraintParameters(m_ConstraintType);
+
+            var applyConstraints = new ApplyBatchedCollisionConstraintsBatchJob()
+            {
+                contacts = ((BurstSolverImpl)constraints.solver).particleContacts,
+
+                simplices = solverImplementation.simplices,
+                simplexCounts = solverImplementation.simplexCounts,
+
+                positions = solverImplementation.positions,
+                deltas = solverImplementation.positionDeltas,
+                counts = solverImplementation.positionConstraintCounts,
+                orientations = solverImplementation.orientations,
+                orientationDeltas = solverImplementation.orientationDeltas,
+                orientationCounts = solverImplementation.orientationConstraintCounts,
+                batchData = batchData,
+                constraintParameters = parameters,
+            };
+
+            int batchCount = batchData.isLast ? batchData.workItemCount : 1;
+            return applyConstraints.Schedule(batchData.workItemCount, batchCount, inputDeps);
+        }
+
+        /**
+         * Updates contact data (contact distance and frame) at the beginning of each substep. This is
+         * necessary because contacts are generated only once at the beginning of each step, not every substep.
+         */
+        [BurstCompile]
+        public struct UpdateParticleContactsJob : IJobParallelFor
+        {
+            [ReadOnly] public NativeArray<float4> prevPositions;
+            [ReadOnly] public NativeArray<quaternion> prevOrientations;
+            [ReadOnly] public NativeArray<float4> velocities;
+            [ReadOnly] public NativeArray<float4> radii;
+            [ReadOnly] public NativeArray<float> invMasses;
+            [ReadOnly] public NativeArray<float4> invInertiaTensors;
+
+            [ReadOnly] public NativeArray<int> particleMaterialIndices;
+            [ReadOnly] public NativeArray<BurstCollisionMaterial> collisionMaterials;
+
+            // simplex arrays:
+            [ReadOnly] public NativeArray<int> simplices;
+            [ReadOnly] public SimplexCounts simplexCounts;
+
+            [NativeDisableContainerSafetyRestriction] [NativeDisableParallelForRestriction] public NativeArray<BurstContact> contacts;
+
+            [ReadOnly] public BatchData batchData;
+
+            public void Execute(int workItemIndex)
+            {
+                int start, end;
+                batchData.GetConstraintRange(workItemIndex, out start, out end);
+
+                for (int i = start; i < end; ++i)
+                {
+                    var contact = contacts[i];
+
+                    int simplexStartA = simplexCounts.GetSimplexStartAndSize(contact.bodyA, out int simplexSizeA);
+                    int simplexStartB = simplexCounts.GetSimplexStartAndSize(contact.bodyB, out int simplexSizeB);
+
+                    float4 simplexVelocityA = float4.zero;
+                    float4 simplexPrevPositionA = float4.zero;
+                    quaternion simplexPrevOrientationA = new quaternion(0, 0, 0, 0);
+                    float simplexRadiusA = 0;
+                    float simplexInvMassA = 0;
+                    float4 simplexInvInertiaA = float4.zero;
+
+                    float4 simplexVelocityB = float4.zero;
+                    float4 simplexPrevPositionB = float4.zero;
+                    quaternion simplexPrevOrientationB = new quaternion(0, 0, 0, 0);
+                    float simplexRadiusB = 0;
+                    float simplexInvMassB = 0;
+                    float4 simplexInvInertiaB = float4.zero;
+
+                    for (int j = 0; j < simplexSizeA; ++j)
+                    {
+                        int particleIndex = simplices[simplexStartA + j];
+                        simplexVelocityA += velocities[particleIndex] * contact.pointA[j];
+                        simplexPrevPositionA += prevPositions[particleIndex] * contact.pointA[j];
+                        simplexPrevOrientationA.value += prevOrientations[particleIndex].value * contact.pointA[j];
+                        simplexInvMassA += invMasses[particleIndex] * contact.pointA[j];
+                        simplexInvInertiaA += invInertiaTensors[particleIndex] * contact.pointA[j];
+                        simplexRadiusA += BurstMath.EllipsoidRadius(contact.normal, prevOrientations[particleIndex], radii[particleIndex].xyz) * contact.pointA[j];
+                    }
+
+                    for (int j = 0; j < simplexSizeB; ++j)
+                    {
+                        int particleIndex = simplices[simplexStartB + j];
+                        simplexVelocityB += velocities[particleIndex] * contact.pointB[j];
+                        simplexPrevPositionB += prevPositions[particleIndex] * contact.pointB[j];
+                        simplexPrevOrientationB.value += prevOrientations[particleIndex].value * contact.pointB[j];
+                        simplexInvMassB += invMasses[particleIndex] * contact.pointB[j];
+                        simplexInvInertiaB += invInertiaTensors[particleIndex] * contact.pointB[j];
+                        simplexRadiusB += BurstMath.EllipsoidRadius(contact.normal, prevOrientations[particleIndex], radii[particleIndex].xyz) * contact.pointB[j];
+                    }
+
+                    // update contact distance
+                    float dAB = math.dot(simplexPrevPositionA - simplexPrevPositionB, contact.normal);
+                    contact.distance = dAB - (simplexRadiusA + simplexRadiusB);
+
+                    // calculate contact points:
+                    float4 contactPointA = simplexPrevPositionB + contact.normal * (contact.distance + simplexRadiusB);
+                    float4 contactPointB = simplexPrevPositionA - contact.normal * (contact.distance + simplexRadiusA);
+
+                    // update contact basis:
+                    contact.CalculateBasis(simplexVelocityA - simplexVelocityB);
+
+                    // update contact masses:
+                    int aMaterialIndex = particleMaterialIndices[simplices[simplexStartA]];
+                    int bMaterialIndex = particleMaterialIndices[simplices[simplexStartB]];
+                    bool rollingContacts = (aMaterialIndex >= 0 ? collisionMaterials[aMaterialIndex].rollingContacts > 0 : false) |
+                                           (bMaterialIndex >= 0 ? collisionMaterials[bMaterialIndex].rollingContacts > 0 : false);
+
+                    contact.CalculateContactMassesA(simplexInvMassA, simplexInvInertiaA, simplexPrevPositionA, simplexPrevOrientationA, contactPointA, rollingContacts);
+                    contact.CalculateContactMassesB(simplexInvMassB, simplexInvInertiaB, simplexPrevPositionB, simplexPrevOrientationB, contactPointB, rollingContacts);
+
+                    contacts[i] = contact;
+                }
+            }
+        }
+
+        [BurstCompile]
+        public struct ParticleCollisionConstraintsBatchJob : IJobParallelFor
+        {
+            [ReadOnly] public NativeArray<quaternion> orientations;
+            [ReadOnly] public NativeArray<float> invMasses;
+            [ReadOnly] public NativeArray<float4> radii;
+            [ReadOnly] public NativeArray<int> particleMaterialIndices;
+            [ReadOnly] public NativeArray<BurstCollisionMaterial> collisionMaterials;
+
+            // simplex arrays:
+            [ReadOnly] public NativeArray<int> simplices;
+            [ReadOnly] public SimplexCounts simplexCounts;
+
+            [NativeDisableContainerSafetyRestriction] [NativeDisableParallelForRestriction] public NativeArray<float4> positions;
+            [NativeDisableContainerSafetyRestriction] [NativeDisableParallelForRestriction] public NativeArray<float4> deltas;
+            [NativeDisableContainerSafetyRestriction] [NativeDisableParallelForRestriction] public NativeArray<int> counts;
+            [NativeDisableContainerSafetyRestriction] [NativeDisableParallelForRestriction] public NativeArray<BurstContact> contacts;
+
+            [ReadOnly] public Oni.ConstraintParameters constraintParameters;
+            [ReadOnly] public Oni.SolverParameters solverParameters;
+            [ReadOnly] public float4 gravity;
+            [ReadOnly] public float substepTime;
+
+            [ReadOnly] public BatchData batchData;
+
+            public void Execute(int workItemIndex)
+            {
+                int start, end;
+                batchData.GetConstraintRange(workItemIndex, out start, out end);
+
+                for (int i = start; i < end; ++i)
+                {
+                    var contact = contacts[i];
+
+                    int simplexStartA = simplexCounts.GetSimplexStartAndSize(contact.bodyA, out int simplexSizeA);
+                    int simplexStartB = simplexCounts.GetSimplexStartAndSize(contact.bodyB, out int simplexSizeB);
+
+
+                    // Combine collision materials:
+                    BurstCollisionMaterial material = CombineCollisionMaterials(simplices[simplexStartA], simplices[simplexStartB]);
+
+                    float4 simplexPositionA = float4.zero, simplexPositionB = float4.zero;
+                    float simplexRadiusA = 0, simplexRadiusB = 0;
+
+                    for (int j = 0; j < simplexSizeA; ++j)
+                    {
+                        int particleIndex = simplices[simplexStartA + j];
+                        simplexPositionA += positions[particleIndex] * contact.pointA[j];
+                        simplexRadiusA += BurstMath.EllipsoidRadius(contact.normal, orientations[particleIndex], radii[particleIndex].xyz) * contact.pointA[j];
+                    }
+                    for (int j = 0; j < simplexSizeB; ++j)
+                    {
+                        int particleIndex = simplices[simplexStartB + j];
+                        simplexPositionB += positions[particleIndex] * contact.pointB[j];
+                        simplexRadiusB += BurstMath.EllipsoidRadius(contact.normal, orientations[particleIndex], radii[particleIndex].xyz) * contact.pointA[j];
+                    }
+
+                    float4 posA = simplexPositionA - contact.normal * simplexRadiusA;
+                    float4 posB = simplexPositionB + contact.normal * simplexRadiusB;
+
+                    // adhesion:
+                    float lambda = contact.SolveAdhesion(posA, posB, material.stickDistance, material.stickiness, substepTime);
+
+                    // depenetration:
+                    lambda += contact.SolvePenetration(posA, posB, solverParameters.maxDepenetration * substepTime);
+
+                    // Apply normal impulse to both particles (w/ shock propagation):
+                    if (math.abs(lambda) > BurstMath.epsilon)
+                    {
+                        float shock = solverParameters.shockPropagation * math.dot(contact.normal, math.normalizesafe(gravity));
+                        float4 delta = lambda * contact.normal;
+
+                        float baryScale = BurstMath.BaryScale(contact.pointA);
+                        for (int j = 0; j < simplexSizeA; ++j)
+                        {
+                            int particleIndex = simplices[simplexStartA + j];
+                            deltas[particleIndex] += delta * invMasses[particleIndex] * contact.pointA[j] * baryScale * (1 - shock);
+                            counts[particleIndex]++;
+                        }
+
+                        baryScale = BurstMath.BaryScale(contact.pointB);
+                        for (int j = 0; j < simplexSizeB; ++j)
+                        {
+                            int particleIndex = simplices[simplexStartB + j];
+                            deltas[particleIndex] -= delta * invMasses[particleIndex] * contact.pointB[j] * baryScale * (1 + shock);
+                            counts[particleIndex]++;
+                        }
+                    }
+
+                    // Apply position deltas immediately, if using sequential evaluation:
+                    if (constraintParameters.evaluationOrder == Oni.ConstraintParameters.EvaluationOrder.Sequential)
+                    {
+                        for (int j = 0; j < simplexSizeA; ++j)
+                        {
+                            int particleIndex = simplices[simplexStartA + j];
+                            BurstConstraintsBatchImpl.ApplyPositionDelta(particleIndex, constraintParameters.SORFactor, ref positions, ref deltas, ref counts);
+                        }
+
+                        for (int j = 0; j < simplexSizeB; ++j)
+                        {
+                            int particleIndex = simplices[simplexStartB + j];
+                            BurstConstraintsBatchImpl.ApplyPositionDelta(particleIndex, constraintParameters.SORFactor, ref positions, ref deltas, ref counts);
+                        }
+                    }
+
+                    contacts[i] = contact;
+                }
+            }
+
+            private BurstCollisionMaterial CombineCollisionMaterials(int entityA, int entityB)
+            {
+                // Combine collision materials:
+                int aMaterialIndex = particleMaterialIndices[entityA];
+                int bMaterialIndex = particleMaterialIndices[entityB];
+
+                if (aMaterialIndex >= 0 && bMaterialIndex >= 0)
+                    return BurstCollisionMaterial.CombineWith(collisionMaterials[aMaterialIndex], collisionMaterials[bMaterialIndex]);
+                else if (aMaterialIndex >= 0)
+                    return collisionMaterials[aMaterialIndex];
+                else if (bMaterialIndex >= 0)
+                    return collisionMaterials[bMaterialIndex];
+
+                return new BurstCollisionMaterial();
+            }
+        }
+
+
+    }
+}
+#endif