274 lines
8.6 KiB
C#
274 lines
8.6 KiB
C#
using UnityEngine;
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using System.Collections.Generic;
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public class RaycastShadowCollider : MonoBehaviour
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{
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public Light spotLight;
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public List<GameObject> shadowCasters = new List<GameObject>();
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public LayerMask shadowCasterLayer;
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public LayerMask shadowReceiverLayer;
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public float maxShadowDistance = 10f;
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public PolygonCollider2D shadowCollider;
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void Start()
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{
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UpdateShadowColliders();
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}
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void Update()
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{
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//UpdateShadowCollider();
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}
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void UpdateShadowColliders()
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{
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foreach (var shadowCaster in shadowCasters)
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{
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UpdateShadowCollider(shadowCaster);
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}
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}
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void UpdateShadowCollider(GameObject shadowCaster)
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{
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List<Vector2> shadowPoints = new List<Vector2>();
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// 获取阴影投射器的边界点（世界坐标）
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Vector3[] worldBoundPoints = GetBoundPoints(shadowCaster);
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foreach (Vector3 worldPoint in worldBoundPoints)
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{
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// 方向：从灯光指向边界点
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Vector3 toPoint = (worldPoint - spotLight.transform.position).normalized;
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// 创建从灯光位置发出的射线
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Ray ray = new Ray(spotLight.transform.position, toPoint);
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RaycastHit hit;
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// 调试：显示射线方向
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Debug.DrawRay(spotLight.transform.position, toPoint * maxShadowDistance, Color.yellow);
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if (Physics.Raycast(ray, out hit, maxShadowDistance, shadowReceiverLayer))
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{
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// 检查是否击中了阴影投射器
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if (hit.collider.gameObject == gameObject)
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{
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// 将世界坐标的碰撞点转换到阴影碰撞器的本地坐标
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Vector3 localHit = shadowCollider.transform.InverseTransformPoint(hit.point);
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shadowPoints.Add(new Vector2(localHit.x, localHit.y));
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// 调试：在碰撞点创建小球
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// GameObject sphere = GameObject.CreatePrimitive(PrimitiveType.Sphere);
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//sphere.transform.position = hit.point;
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// sphere.transform.localScale = Vector3.one * 0.1f;
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//Destroy(sphere, 0.1f);
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}
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}
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//else
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//{
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// // 如果没有击中，使用最大距离的点
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// Vector3 maxPoint = spotLight.transform.position + toPoint * maxShadowDistance;
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// Vector3 localMaxPoint = shadowCollider.transform.InverseTransformPoint(maxPoint);
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// shadowPoints.Add(new Vector2(localMaxPoint.x, localMaxPoint.y));
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// // 调试：在最大距离点创建小球
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// GameObject sphere = GameObject.CreatePrimitive(PrimitiveType.Sphere);
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// sphere.transform.position = maxPoint;
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// sphere.transform.localScale = Vector3.one * 0.1f;
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// sphere.GetComponent<Renderer>().material.color = Color.blue;
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// Destroy(sphere, 0.1f);
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//}
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}
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// 设置碰撞器路径
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if (shadowPoints.Count > 2)
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{
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// 对点进行排序以确保正确的多边形
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shadowPoints = SortShadowPoints(shadowPoints);
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shadowCollider.SetPath(0, shadowPoints);
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}
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else
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{
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shadowCollider.pathCount = 0;
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}
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}
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Vector3[] GetBoundPoints(GameObject target)
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{
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Bounds bounds = target.GetComponent<MeshRenderer>().bounds;
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return new Vector3[]
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{
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bounds.min,
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bounds.max,
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new Vector3(bounds.min.x, bounds.min.y, bounds.max.z),
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new Vector3(bounds.min.x, bounds.max.y, bounds.min.z),
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new Vector3(bounds.max.x, bounds.min.y, bounds.min.z),
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new Vector3(bounds.min.x, bounds.max.y, bounds.max.z),
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new Vector3(bounds.max.x, bounds.min.y, bounds.max.z),
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new Vector3(bounds.max.x, bounds.max.y, bounds.min.z)
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};
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}
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//List<Vector2> SortPointsClockwise(List<Vector2> points)
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//{
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// if (points.Count < 3) return points;
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// // 计算中心点
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// Vector2 center = Vector2.zero;
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// foreach (Vector2 point in points)
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// {
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// center += point;
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// }
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// center /= points.Count;
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// // 按角度排序
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// points.Sort((a, b) =>
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// {
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// Vector2 dirA = a - center;
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// Vector2 dirB = b - center;
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// float angleA = Mathf.Atan2(dirA.y, dirA.x);
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// float angleB = Mathf.Atan2(dirB.y, dirB.x);
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// return angleA.CompareTo(angleB);
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// });
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// points.Add(points[points.Count-1]);
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// return points;
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//}
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List<Vector2> SortPointsClockwise(List<Vector2> points)
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{
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if (points.Count < 3) return points;
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// 方法1：使用凸包算法（推荐）
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List<Vector2> convexHull = ComputeConvexHull(points);
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return convexHull;
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// 或者方法2：改进的角度排序（如果确定是凸多边形）
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// return ImprovedAngleSort(points);
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}
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// 计算凸包 - Graham Scan 算法
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List<Vector2> ComputeConvexHull(List<Vector2> points)
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{
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if (points.Count < 3) return points;
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// 找到最左下角的点作为起点
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Vector2 startPoint = points[0];
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foreach (Vector2 point in points)
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{
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if (point.y < startPoint.y || (point.y == startPoint.y && point.x < startPoint.x))
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{
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startPoint = point;
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}
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}
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// 按极角排序
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List<Vector2> sortedPoints = new List<Vector2>(points);
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sortedPoints.Sort((a, b) =>
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{
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if (a == startPoint) return -1;
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if (b == startPoint) return 1;
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Vector2 dirA = a - startPoint;
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Vector2 dirB = b - startPoint;
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float cross = Cross(dirA, dirB);
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if (Mathf.Abs(cross) < 0.001f) // 共线情况
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{
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return dirA.sqrMagnitude.CompareTo(dirB.sqrMagnitude);
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}
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return cross > 0 ? -1 : 1;
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});
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// 构建凸包
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List<Vector2> hull = new List<Vector2>();
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hull.Add(startPoint);
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hull.Add(sortedPoints[1]);
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for (int i = 2; i < sortedPoints.Count; i++)
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{
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while (hull.Count >= 2)
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{
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Vector2 a = hull[hull.Count - 2];
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Vector2 b = hull[hull.Count - 1];
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Vector2 c = sortedPoints[i];
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if (Cross(b - a, c - a) <= 0)
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{
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hull.RemoveAt(hull.Count - 1);
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}
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else
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{
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break;
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}
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}
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hull.Add(sortedPoints[i]);
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}
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return hull;
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}
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// 叉积计算
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float Cross(Vector2 a, Vector2 b)
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{
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return a.x * b.y - a.y * b.x;
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}
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// 改进的角度排序（仅适用于凸多边形）
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List<Vector2> ImprovedAngleSort(List<Vector2> points)
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{
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// 计算中心点
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Vector2 center = Vector2.zero;
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foreach (Vector2 point in points)
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{
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center += point;
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}
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center /= points.Count;
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// 按角度排序，处理相同角度的情况
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points.Sort((a, b) =>
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{
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Vector2 dirA = a - center;
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Vector2 dirB = b - center;
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float angleA = Mathf.Atan2(dirA.y, dirA.x);
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float angleB = Mathf.Atan2(dirB.y, dirB.x);
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// 处理角度接近的情况
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if (Mathf.Abs(angleA - angleB) < 0.001f)
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{
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return dirA.sqrMagnitude.CompareTo(dirB.sqrMagnitude);
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}
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return angleA.CompareTo(angleB);
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});
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return points;
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}
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// 专门为阴影投影点设计的排序方法
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List<Vector2> SortShadowPoints(List<Vector2> points)
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{
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if (points.Count < 3) return points;
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// 对于阴影点，通常形成凸多边形，使用凸包算法
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List<Vector2> hull = ComputeConvexHull(points);
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// 确保点是顺时针顺序（Unity碰撞器需要）
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if (!IsClockwise(hull))
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{
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hull.Reverse();
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}
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return hull;
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}
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// 检查多边形是否是顺时针顺序
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bool IsClockwise(List<Vector2> points)
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{
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float area = 0;
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for (int i = 0; i < points.Count; i++)
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{
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Vector2 current = points[i];
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Vector2 next = points[(i + 1) % points.Count];
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area += (next.x - current.x) * (next.y + current.y);
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}
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return area > 0;
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}
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} |