【Unity小技巧】Unity中实现带有Sprite Shape的2D水效果（附项目源码）

[ExecuteAlways]
public class WaterShapeController : MonoBehaviour
{
    private int CorsnersCount = 2; // 水形状的边角数
    [SerializeField]
    private SpriteShapeController spriteShapeController; // 水形状控制器
    [SerializeField, Header("波浪点预设物体")]
    private GameObject wavePointPref;
    [SerializeField, Header("波浪点父物体")]
    private GameObject wavePoints;

    [SerializeField, Header("波浪数量")]
    [Range(1, 100)]
    private int WavesCount;
    private List<WaterSpring> springs = new(); // 存储水波浪效果的弹簧节点
    [Header("弹簧的强度常数")]
    public float springStiffness = 0.1f;
    [Header("阻力，用于减缓弹簧的运动")]
    public float dampening = 0.03f;
    [Header("扩散常数，用于将节点的影响传递给它附近的节点")]
    public float spread = 0.006f;

    void Start()
    {

    }
    void OnValidate()
    {
        // 清空水波浪点和弹簧
        StartCoroutine(CreateWaves());
    }
    IEnumerator CreateWaves()
    {
        foreach (Transform child in wavePoints.transform)
        {
            StartCoroutine(Destroy(child.gameObject));
        }
        yield return null;
        SetWaves();
        yield return null;
    }
    IEnumerator Destroy(GameObject go)
    {
        yield return null;
        DestroyImmediate(go);
    }
    private void SetWaves()
    {
        Spline waterSpline = spriteShapeController.spline; // 获取水形状的样条曲线
        int waterPointsCount = waterSpline.GetPointCount(); // 获取水形状的点数

        // 移除中间点，只保留边角的两个点
        // 每次移除第一个点，则第二个点成为新的第一个点
        for (int i = CorsnersCount; i < waterPointsCount - CorsnersCount; i++)
        {
            waterSpline.RemovePointAt(CorsnersCount);
        }

        Vector3 waterTopLeftCorner = waterSpline.GetPosition(1); // 水形状左上角的顶点位置
        Vector3 waterTopRightCorner = waterSpline.GetPosition(2); // 水形状右上角的顶点位置
        float waterWidth = waterTopRightCorner.x - waterTopLeftCorner.x; // 水形状的宽度

        float spacingPerWave = waterWidth / (WavesCount + 1); // 计算每个波浪之间的间隔
                                                              // 在水形状中添加波浪点
        for (int i = WavesCount; i > 0; i--)
        {
            int index = CorsnersCount;

            float xPosition = waterTopLeftCorner.x + (spacingPerWave * i);
            Vector3 wavePoint = new Vector3(xPosition, waterTopLeftCorner.y, waterTopLeftCorner.z);
            waterSpline.InsertPointAt(index, wavePoint);
            waterSpline.SetHeight(index, 0.1f);
            waterSpline.SetCorner(index, false);
            waterSpline.SetTangentMode(index, ShapeTangentMode.Continuous);
        }

        springs = new();
        for (int i = 0; i <= WavesCount + 1; i++)
        {
            int index = i + 1;

            Smoothen(waterSpline, index); // 平滑水形状的曲线

            GameObject wavePoint = Instantiate(wavePointPref, wavePoints.transform, false);
            wavePoint.transform.localPosition = waterSpline.GetPosition(index);

            WaterSpring waterSpring = wavePoint.GetComponent<WaterSpring>();
            waterSpring.Init(spriteShapeController);
            springs.Add(waterSpring);
        }
    }
    private void Smoothen(Spline waterSpline, int index)
    {
        Vector3 position = waterSpline.GetPosition(index); // 获取节点位置
        Vector3 positionPrev = position;
        Vector3 positionNext = position;
        if (index > 1)
        {
            positionPrev = waterSpline.GetPosition(index - 1); // 获取上一个节点的位置
        }
        if (index - 1 <= WavesCount)
        {
            positionNext = waterSpline.GetPosition(index + 1); // 获取下一个节点的位置
        }

        Vector3 forward = gameObject.transform.forward;

        float scale = Mathf.Min((positionNext - position).magnitude, (positionPrev - position).magnitude) * 0.33f;

        Vector3 leftTangent = (positionPrev - position).normalized * scale;
        Vector3 rightTangent = (positionNext - position).normalized * scale;

        SplineUtility.CalculateTangents(position, positionPrev, positionNext, forward, scale, out rightTangent, out leftTangent);

        waterSpline.SetLeftTangent(index, leftTangent); // 设置左切向量
        waterSpline.SetRightTangent(index, rightTangent); // 设置右切向量
    }
    void FixedUpdate()
    {
        foreach (WaterSpring waterSpringComponent in springs)
        {
            waterSpringComponent.WaveSpringUpdate(springStiffness, dampening); // 更新弹簧效果
            waterSpringComponent.WavePointUpdate(); // 更新节点位置
        }

        UpdateSprings(); // 更新所有弹簧的速度

    }

    private void UpdateSprings()
    {
        int count = springs.Count;
        float[] left_deltas = new float[count];
        float[] right_deltas = new float[count];

        for (int i = 0; i < count; i++)
        {
            if (i > 0)
            {
                left_deltas[i] = spread * (springs[i].height - springs[i - 1].height);
                springs[i - 1].velocity += left_deltas[i];
            }
            if (i < springs.Count - 1)
            {
                right_deltas[i] = spread * (springs[i].height - springs[i + 1].height);
                springs[i + 1].velocity += right_deltas[i];
            }
        }
    }
    private void Splash(int index, float speed)
    {
        if (index >= 0 && index < springs.Count)
        {
            springs[index].velocity += speed;
        }
    }
}