这里使用一种更高效地从深度纹理中重建世界坐标的方法。
首先计算摄像机的视锥体的四条射线向量进行线性插值，插值后的值便是该像素在世界空间坐标下到摄像机的方向。
然后通过与深度值相乘即可得到摄像机位置到该像素的向量，加上摄像机的位置则是该像素在世界空间中的位置。
转载请注明出处：https://www.cnblogs.com/jietian331/p/9443343.html
c#代码：
1 using UnityEngine; 2 3 public class HighFog2 : PostEffectRenderer 4 { 5 [SerializeField] 6 Color m_fogColor = Color.white; 7 [Range(0f, 1f)] 8 [SerializeField] 9 float m_fogDensity = 0.9f; 10 [SerializeField] 11 float m_fogPosY = 0.1f; 12 [SerializeField] 13 float m_fogDisappearHeight = 8; 14 15 16 protected override string ShaderName 17 { 18 get { return "Custom/Study/HighFog2"; } 19 } 20 21 protected override void OnRenderImage(RenderTexture src, RenderTexture dest) 22 { 23 float fov = base.SelfCamera.fieldOfView; 24 float near = base.SelfCamera.nearClipPlane; 25 Transform camT = base.SelfCamera.transform; 26 27 float halfFOV = fov * Mathf.PI / 360f; 28 float toTopDis = near * Mathf.Tan(halfFOV); 29 float toRightDis = toTopDis * (Screen.width / Screen.height); 30 Vector3 toTop = camT.up * toTopDis; 31 Vector3 toRight = camT.right * toRightDis; 32 Vector3 toCenter = camT.forward * near; 33 Vector3 topLeft = (toCenter + toTop - toRight) / near; 34 Vector3 topRight = (toCenter + toTop + toRight) / near; 35 Vector3 bottomLeft = (toCenter - toTop - toRight) / near; 36 Vector3 bottomRight = (toCenter - toTop - toRight) / near; 37 38 Matrix4x4 matrix = Matrix4x4.identity; 39 matrix.SetRow(0, bottomLeft); 40 matrix.SetRow(1, bottomRight); 41 matrix.SetRow(2, topLeft); 42 matrix.SetRow(3, topRight); 43 44 base.Mat.SetMatrix("_CameraRays", matrix); 45 base.Mat.SetColor("_FogColor", m_fogColor); 46 base.Mat.SetFloat("_FogDensity", m_fogDensity); 47 base.Mat.SetFloat("_FogPosY", m_fogPosY); 48 base.Mat.SetFloat("_FogDisappearHeight", m_fogDisappearHeight); 49 base.OnRenderImage(src, dest); 50 } 51 }