去掉obi，使用自写绳索

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

@@ -1,65 +0,0 @@
-#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