82 lines
2.5 KiB
C#
82 lines
2.5 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; // 聚光灯
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public GameObject shadowCaster; // 投射阴影的物体
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public int rayCount = 36; // 光线数量
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public float maxShadowDistance = 10f;
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private PolygonCollider2D shadowCollider;
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void Start()
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{
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shadowCollider = GetComponent<PolygonCollider2D>();
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if (shadowCollider == null)
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shadowCollider = gameObject.AddComponent<PolygonCollider2D>();
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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 UpdateShadowCollider()
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{
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List<Vector2> shadowPoints = new List<Vector2>();
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// 从物体边界点向灯光方向投射光线
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Bounds bounds = shadowCaster.GetComponent<Renderer>().bounds;
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Vector3[] boundPoints = GetBoundPoints(bounds);
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foreach (Vector3 point in boundPoints)
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{
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Vector3 toLight = (spotLight.transform.position - point).normalized;
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Ray ray = new Ray(point, toLight);
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RaycastHit hit;
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if (Physics.Raycast(ray, out hit, maxShadowDistance))
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{
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if (hit.collider.gameObject == gameObject) // 击中墙面
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{
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// 转换到墙面的局部坐标系
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Vector3 localHit = transform.InverseTransformPoint(hit.point);
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shadowPoints.Add(new Vector2(localHit.x, localHit.y));
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}
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}
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}
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// 对点进行排序，形成凸包
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if (shadowPoints.Count > 2)
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{
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List<Vector2> convexHull = ComputeConvexHull(shadowPoints);
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shadowCollider.SetPath(0, convexHull);
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}
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}
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Vector3[] GetBoundPoints(Bounds bounds)
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{
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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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// 凸包算法（Graham Scan）
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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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// 实现凸包算法...
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// 这里可以使用Unity的Collider2D.CreatePrimitive或者第三方库
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return points; // 简化返回
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}
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} |