浮漂逻辑

Assets/Scripts/Test/BuoyancyBody.cs

@@ -2,17 +2,7 @@
 using System.Collections.Generic;
 using UnityEngine;
 
-public interface IWaterProvider
-{
-    /// <summary>返回该世界坐标下的水面高度</summary>
-    float GetWaterHeight(Vector3 worldPos);
 
-    /// <summary>可选：水面法线（没有就返回 Vector3.up）</summary>
-    Vector3 GetWaterNormal(Vector3 worldPos);
-
-    /// <summary>可选：水流速度（没有就返回 Vector3.zero）</summary>
-    Vector3 GetWaterVelocity(Vector3 worldPos);
-}
 
 /// <summary>
 /// 多点采样浮力：考虑形状(采样点分布)、重心(Rigidbody.centerOfMass)、扭矩(在点上施力)。

Assets/Scripts/Test/BuoyancyCapsuleSphere.cs

@@ -0,0 +1,224 @@
+using UnityEngine;
+
+public interface IWaterProvider
+{
+    float GetWaterHeight(Vector3 worldPos);
+    Vector3 GetWaterNormal(Vector3 worldPos);
+    Vector3 GetWaterVelocity(Vector3 worldPos);
+}
+
+/// <summary>
+/// 稳定优先的浮力（只支持 CapsuleCollider / SphereCollider）
+/// - 竖直方向：目标吃水深度 + PD 控制（稳定，不抖、不弹飞）
+/// - 姿态：Righting Torque 扶正（受 Rigidbody.centerOfMass 影响）
+/// - 入水比例：带平滑（避免水面附近开关抖动）
+/// </summary>
+[DisallowMultipleComponent]
+[RequireComponent(typeof(Rigidbody))]
+public class BuoyancyCapsuleSphere : MonoBehaviour
+{
+    [Header("Collider (choose one)")]
+    public CapsuleCollider capsule;
+    public SphereCollider sphere;
+
+    [Header("Water")]
+    public MonoBehaviour waterProviderBehaviour; // 可选
+    private IWaterProvider waterProvider;
+
+    [Tooltip("没有 provider 时的水面高度")]
+    public float waterLevel = 0f;
+
+    [Header("Density -> Draft")]
+    [Tooltip("水密度 kg/m^3（淡水约1000）")]
+    public float waterDensity = 1000f;
+
+    [Tooltip("物体等效密度 kg/m^3。越小越浮。浮漂可 80~400 之间调")]
+    public float objectDensity = 250f;
+
+    [Tooltip("额外浮力比例（手感调整）。1=按密度算")]
+    public float buoyancyScale = 1f;
+
+    [Header("Vertical PD (Stability key)")]
+    [Tooltip("竖直弹簧强度（越大越“顶住”目标吃水）")]
+    public float verticalKp = 35f;
+
+    [Tooltip("竖直阻尼（越大越不弹、不抖）")]
+    public float verticalKd = 12f;
+
+    [Tooltip("最大向上加速度 m/s^2（防止从高处落下入水被顶飞）")]
+    public float maxUpAccel = 25f;
+
+    [Tooltip("最大向下加速度 m/s^2（防止强行拉下去造成抖动）")]
+    public float maxDownAccel = 10f;
+
+    [Header("Submergence smoothing")]
+    [Tooltip("入水比例变化速度（1/s）。越大越快响应，越小越稳")]
+    public float submergenceSpeed = 8f;
+
+    [Tooltip("水面外的缓冲(m)，让浮力更平滑接管")]
+    public float surfaceMargin = 0.01f;
+
+    [Header("Righting (Rotation)")]
+    [Tooltip("扶正强度（把 transform.up 拉向水面法线/世界上）")]
+    public float rightingKp = 8f;
+
+    [Tooltip("扶正阻尼（抑制旋转抖动）")]
+    public float rightingKd = 3f;
+
+    [Header("Water drag (optional but helpful)")]
+    [Tooltip("入水时额外线阻尼（通过 rb.drag 混合）")]
+    public float extraLinearDragInWater = 2.5f;
+
+    [Tooltip("入水时额外角阻尼（通过 rb.angularDrag 混合）")]
+    public float extraAngularDragInWater = 2.0f;
+
+    [Header("Center of Mass")]
+    [Tooltip("本地重心偏移：例如 (0,-0.02,0) 让底部更重、更容易站漂")]
+    public Vector3 centerOfMassOffset = Vector3.zero;
+
+    private Rigidbody rb;
+    private float baseDrag, baseAngularDrag;
+
+    // 关键：入水比例必须有“记忆”（滤波），否则水面边界必抖
+    private float subFiltered = 0f;
+
+    void Reset()
+    {
+        rb = GetComponent<Rigidbody>();
+        rb.useGravity = true;
+        rb.interpolation = RigidbodyInterpolation.Interpolate;
+        rb.collisionDetectionMode = CollisionDetectionMode.Continuous;
+
+        capsule = GetComponent<CapsuleCollider>();
+        sphere = GetComponent<SphereCollider>();
+    }
+
+    void Awake()
+    {
+        rb = GetComponent<Rigidbody>();
+        rb.centerOfMass = centerOfMassOffset;
+
+        baseDrag = rb.linearDamping;
+        baseAngularDrag = rb.angularDamping;
+
+        waterProvider = waterProviderBehaviour as IWaterProvider;
+
+        // 只允许一个
+        if (capsule != null && sphere != null)
+            sphere = null;
+    }
+
+    void OnValidate()
+    {
+        objectDensity = Mathf.Max(1e-3f, objectDensity);
+        waterDensity = Mathf.Max(1e-3f, waterDensity);
+        submergenceSpeed = Mathf.Max(0.1f, submergenceSpeed);
+        surfaceMargin = Mathf.Max(0f, surfaceMargin);
+        maxUpAccel = Mathf.Max(0f, maxUpAccel);
+        maxDownAccel = Mathf.Max(0f, maxDownAccel);
+    }
+
+    void FixedUpdate()
+    {
+        if (!capsule && !sphere) return;
+
+        waterProvider = waterProviderBehaviour as IWaterProvider;
+
+        // 取“浮体中心点”作为控制点（稳定，不戳点）
+        Vector3 centerWorld;
+        float shapeHeight; // 近似“高度”（sphere=直径，capsule=高度）
+        GetCenterAndHeight(out centerWorld, out shapeHeight);
+
+        // 水面信息
+        float waterH = (waterProvider != null) ? waterProvider.GetWaterHeight(centerWorld) : waterLevel;
+        Vector3 waterN = (waterProvider != null) ? waterProvider.GetWaterNormal(centerWorld) : Vector3.up;
+        if (waterN.sqrMagnitude < 1e-6f) waterN = Vector3.up;
+        waterN.Normalize();
+
+        // 当前中心“浸没深度”(>0 表示中心在水下)
+        float centerDepth = waterH - centerWorld.y;
+
+        // 近似入水比例：centerDepth = -H/2 -> 0; centerDepth = +H/2 -> 1
+        float rawSub = Mathf.Clamp01((centerDepth + (shapeHeight * 0.5f) + surfaceMargin) / (shapeHeight + 2f * surfaceMargin));
+
+        // 入水比例滤波（非常关键）
+        float dt = Time.fixedDeltaTime;
+        subFiltered = Mathf.MoveTowards(subFiltered, rawSub, submergenceSpeed * dt);
+
+        // 混合拖拽（让水中更稳）
+        rb.linearDamping = Mathf.Lerp(baseDrag, baseDrag + extraLinearDragInWater, subFiltered);
+        rb.angularDamping = Mathf.Lerp(baseAngularDrag, baseAngularDrag + extraAngularDragInWater, subFiltered);
+
+        if (subFiltered <= 1e-4f)
+            return; // 基本没入水，不做任何浮力/扶正
+
+        // 目标吃水比例：理想静态平衡 ≈ objectDensity / waterDensity（<1 才会浮）
+        float desiredSub = Mathf.Clamp01((objectDensity / waterDensity) * buoyancyScale);
+
+        // 把 desiredSub 转成目标中心深度
+        // desiredSub=0 -> centerDepthTarget = -H/2（完全出水）
+        // desiredSub=1 -> centerDepthTarget = +H/2（完全入水）
+        float centerDepthTarget = desiredSub * shapeHeight - shapeHeight * 0.5f;
+
+        // 竖直 PD：只沿“世界上/重力反方向”控制，最稳
+        Vector3 up = (-Physics.gravity).sqrMagnitude > 1e-6f ? (-Physics.gravity).normalized : Vector3.up;
+        float vUp = Vector3.Dot(rb.linearVelocity, up);
+
+        float error = centerDepth - centerDepthTarget;     // 深了为正 -> 需要向上推
+        float accelUp = (-verticalKp * error) - (verticalKd * vUp);
+
+        // 限制上下加速度，避免顶飞或强拉抖动
+        accelUp = Mathf.Clamp(accelUp, -maxDownAccel, maxUpAccel);
+
+        // 随入水比例渐入（避免水面边界突然接管）
+        accelUp *= subFiltered;
+
+        // 施加竖直加速度（Acceleration 不受质量影响，更稳定）
+        rb.AddForce(up * accelUp, ForceMode.Acceleration);
+
+        // 扶正力矩：把物体 up 拉向 waterN（平静水就是 Vector3.up）
+        // 注意：这个扶正与重心偏移一起工作，会形成“站漂/躺漂”的稳定姿态
+        Vector3 currentUp = transform.up;
+        Vector3 axis = Vector3.Cross(currentUp, waterN);
+
+        // 小角度近似：axis 的大小约等于 sin(theta)
+        // 扶正加速度型扭矩（同样用 Acceleration，减少质量/惯量差带来的抖动）
+        Vector3 angVel = rb.angularVelocity;
+        Vector3 torqueAccel = axis * rightingKp - angVel * rightingKd;
+
+        torqueAccel *= subFiltered;
+
+        rb.AddTorque(torqueAccel, ForceMode.Acceleration);
+    }
+
+    private void GetCenterAndHeight(out Vector3 centerWorld, out float heightWorld)
+    {
+        if (sphere)
+        {
+            // sphere：center + 半径*缩放（近似取最大缩放）
+            Transform t = sphere.transform;
+            centerWorld = t.TransformPoint(sphere.center);
+
+            Vector3 s = t.lossyScale;
+            float r = sphere.radius * Mathf.Max(Mathf.Abs(s.x), Mathf.Abs(s.y), Mathf.Abs(s.z));
+            heightWorld = Mathf.Max(1e-6f, r * 2f);
+            return;
+        }
+
+        // capsule
+        Transform ct = capsule.transform;
+        centerWorld = ct.TransformPoint(capsule.center);
+
+        Vector3 ls = ct.lossyScale;
+        float sx = Mathf.Abs(ls.x), sy = Mathf.Abs(ls.y), sz = Mathf.Abs(ls.z);
+
+        float heightScale = capsule.direction switch
+        {
+            0 => sx,
+            1 => sy,
+            _ => sz,
+        };
+
+        heightWorld = Mathf.Max(1e-6f, capsule.height * heightScale);
+    }
+}

Assets/Scripts/Test/BuoyancyCapsuleSphere.cs.meta

@@ -0,0 +1,3 @@
+fileFormatVersion: 2
+guid: bad586cd447d4271b97ce1cf1c81897a
+timeCreated: 1772460028

Assets/Scripts/Test/CapsuleBuoyancy.cs

@@ -0,0 +1,95 @@
+using UnityEngine;
+
+[RequireComponent(typeof(Rigidbody))]
+[RequireComponent(typeof(CapsuleCollider))]
+public class CapsuleBuoyancy : MonoBehaviour
+{
+    [Header("Water Settings")]
+    public float waterHeight = 0f;          // 水面高度
+    public float waterDensity = 1000f;      // 水密度
+
+    [Header("Buoyancy Settings")]
+    public int samplePoints = 8;            // 采样点数量
+    public float buoyancyMultiplier = 1.0f; // 浮力强度调节
+    public float waterDrag = 1.5f;          // 水阻力
+    public float waterAngularDrag = 1.5f;   // 水角阻力
+
+    private Rigidbody rb;
+    private CapsuleCollider capsule;
+
+    private float capsuleVolume;
+    private float gravity;
+
+    void Start()
+    {
+        rb = GetComponent<Rigidbody>();
+        capsule = GetComponent<CapsuleCollider>();
+
+        gravity = Physics.gravity.magnitude;
+
+        CalculateCapsuleVolume();
+    }
+
+    void FixedUpdate()
+    {
+        ApplyBuoyancy();
+    }
+
+    void CalculateCapsuleVolume()
+    {
+        float radius = capsule.radius * Mathf.Max(transform.localScale.x, transform.localScale.z);
+        float height = Mathf.Max(0, capsule.height * transform.localScale.y - 2f * radius);
+
+        float cylinderVolume = Mathf.PI * radius * radius * height;
+        float sphereVolume = (4f / 3f) * Mathf.PI * radius * radius * radius;
+
+        capsuleVolume = cylinderVolume + sphereVolume;
+    }
+
+    void ApplyBuoyancy()
+    {
+        float submergedRatioTotal = 0f;
+
+        for (int i = 0; i < samplePoints; i++)
+        {
+            float t = (float)i / (samplePoints - 1);
+            Vector3 localPoint = Vector3.up * Mathf.Lerp(
+                -capsule.height * 0.5f + capsule.radius,
+                capsule.height * 0.5f - capsule.radius,
+                t);
+
+            Vector3 worldPoint = transform.TransformPoint(localPoint);
+
+            float depth = waterHeight - worldPoint.y;
+
+            if (depth > 0f)
+            {
+                float normalizedDepth = Mathf.Clamp01(depth / (capsule.height / samplePoints));
+                submergedRatioTotal += normalizedDepth;
+
+                float forceMagnitude =
+                    waterDensity *
+                    gravity *
+                    (capsuleVolume / samplePoints) *
+                    normalizedDepth *
+                    buoyancyMultiplier;
+
+                Vector3 buoyancyForce = Vector3.up * forceMagnitude;
+
+                rb.AddForceAtPosition(buoyancyForce, worldPoint, ForceMode.Force);
+            }
+        }
+
+        // 如果在水中，加阻力
+        if (submergedRatioTotal > 0f)
+        {
+            rb.linearDamping = waterDrag;
+            rb.angularDamping = waterAngularDrag;
+        }
+        else
+        {
+            rb.linearDamping = 0f;
+            rb.angularDamping = 0.05f;
+        }
+    }
+}

Assets/Scripts/Test/CapsuleBuoyancy.cs.meta

@@ -0,0 +1,3 @@
+fileFormatVersion: 2
+guid: 3137aa469d6440af8cdeaa03a4c272d1
+timeCreated: 1772464119