unity urp 镜子shader unity做镜子

说明：创建两个代码文件 C#文件复制上MirrorReflection.CS带中文注释 创建Shader文件复制上MirrorReflection.Shader带中文注释 C#代码挂在unity平面片上， 建个材质球选择属性FX/Mirror，创建的Shader文件增加这个属性。 把材质赋予给平面片上，平面片就变成镜面反射了。 然后你在面片旁边加物体挪动，面片里面就会像一面镜子一样 面片背面是隐藏看不见的。 MirrorReflection.CS 代码 using UnityEngine; using System.Collections; // 这实际上是来自标准资产的水脚本， // 只是用折射物去除。 [ExecuteInEditMode] // 即使不在播放模式，也可以进行镜像实时更新 public class MirrorReflection : MonoBehaviour { public bool m_DisablePixelLights = true; public int m_TextureSize = 256; public float m_ClipPlaneOffset = 0.07f; public LayerMask m_ReflectLayers = -1; private Hashtable m_ReflectionCameras = new Hashtable(); // 摄像机>摄像机表 private RenderTexture m_ReflectionTexture = null; private int m_OldReflectionTextureSize = 0; private static bool s_InsideRendering = false; // 当知道对象将由一些人呈现时，这就被调用了。 // 相机。我们在这里渲染倒影并做其他的更新 // 因为脚本是在编辑模式下执行的，所以对场景视图进行了反射。 // 照相机就可以工作了！! public void OnWillRenderObject() { if( !enabled || !GetComponent<Renderer>() || !GetComponent<Renderer>().sharedMaterial || !GetComponent<Renderer>().enabled ) return; Camera cam = Camera.current; if( !cam ) return; // 从递归反射中得到保护 if( s_InsideRendering ) return; s_InsideRendering = true; Camera reflectionCamera; CreateMirrorObjects( cam, out reflectionCamera ); // 找出反射平面：世界空间中的位置和法线 Vector3 pos = transform.position; Vector3 normal = transform.up; // 可选禁用反射像素灯 int oldPixelLightCount = QualitySettings.pixelLightCount; if( m_DisablePixelLights ) QualitySettings.pixelLightCount = 0; UpdateCameraModes( cam, reflectionCamera ); // 渲染反射 // 反射面反射照相机 float d = -Vector3.Dot (normal, pos) - m_ClipPlaneOffset; Vector4 reflectionPlane = new Vector4 (normal.x, normal.y, normal.z, d); Matrix4x4 reflection = Matrix4x4.zero; CalculateReflectionMatrix (ref reflection, reflectionPlane); Vector3 oldpos = cam.transform.position; Vector3 newpos = reflection.MultiplyPoint( oldpos ); reflectionCamera.worldToCameraMatrix = cam.worldToCameraMatrix * reflection; // 设置斜投影矩阵，使近平面成为我们的反射。 // 平面。这样我们就可以把所有的东西都放在下面/上面。 Vector4 clipPlane = CameraSpacePlane( reflectionCamera, pos, normal, 1.0f ); Matrix4x4 projection = cam.projectionMatrix; CalculateObliqueMatrix (ref projection, clipPlane); reflectionCamera.projectionMatrix = projection; reflectionCamera.cullingMask = ~(1<<4) & m_ReflectLayers.value; // 永不渲染水层 reflectionCamera.targetTexture = m_ReflectionTexture; GL.SetRevertBackfacing (true); reflectionCamera.transform.position = newpos; Vector3 euler = cam.transform.eulerAngles; reflectionCamera.transform.eulerAngles = new Vector3(0, euler.y, euler.z); reflectionCamera.Render(); reflectionCamera.transform.position = oldpos; GL.SetRevertBackfacing (false); Material[] materials = GetComponent<Renderer>().sharedMaterials; foreach( Material mat in materials ) { if( mat.HasProperty("_ReflectionTex") ) mat.SetTexture( "_ReflectionTex", m_ReflectionTexture ); } // 设置矩阵变换的UV从对象空间到屏幕材质 // 空间。我们只想在屏幕上投射反射纹理 Matrix4x4 scaleOffset = Matrix4x4.TRS( new Vector3(0.5f,0.5f,0.5f), Quaternion.identity, new Vector3(0.5f,0.5f,0.5f) ); Vector3 scale = transform.lossyScale; Matrix4x4 mtx = transform.localToWorldMatrix * Matrix4x4.Scale( new Vector3(1.0f/scale.x, 1.0f/scale.y, 1.0f/scale.z) ); mtx = scaleOffset * cam.projectionMatrix * cam.worldToCameraMatrix * mtx; foreach( Material mat in materials ) { mat.SetMatrix( "_ProjMatrix", mtx ); } // 恢复像素光计数 if( m_DisablePixelLights ) QualitySettings.pixelLightCount = oldPixelLightCount; s_InsideRendering = false; } // 清理我们可能创建的所有对象 void OnDisable() { if( m_ReflectionTexture ) { DestroyImmediate( m_ReflectionTexture ); m_ReflectionTexture = null; } foreach( DictionaryEntry kvp in m_ReflectionCameras ) DestroyImmediate( ((Camera)kvp.Value).gameObject ); m_ReflectionCameras.Clear(); } private void UpdateCameraModes( Camera src, Camera dest ) { if( dest == null ) return; // 设置相机以与当前相机相同的方式清除 dest.clearFlags = src.clearFlags; dest.backgroundColor = src.backgroundColor; if( src.clearFlags == CameraClearFlags.Skybox ) { Skybox sky = src.GetComponent(typeof(Skybox)) as Skybox; Skybox mysky = dest.GetComponent(typeof(Skybox)) as Skybox; if( !sky || !sky.material ) { mysky.enabled = false; } else { mysky.enabled = true; mysky.material = sky.material; } } // 更新其他值以匹配当前相机。 // 即使我们提供定制的相机和投影矩阵 // 一些价值被用在其他地方（例如Skybox利用远平面） dest.farClipPlane = src.farClipPlane; dest.nearClipPlane = src.nearClipPlane; dest.orthographic = src.orthographic; dest.fieldOfView = src.fieldOfView; dest.aspect = src.aspect; dest.orthographicSize = src.orthographicSize; } // 按需创建任何我们需要的对象 private void CreateMirrorObjects( Camera currentCamera, out Camera reflectionCamera ) { reflectionCamera = null; // 反射的渲染纹理 if( !m_ReflectionTexture || m_OldReflectionTextureSize != m_TextureSize ) { if( m_ReflectionTexture ) DestroyImmediate( m_ReflectionTexture ); m_ReflectionTexture = new RenderTexture( m_TextureSize, m_TextureSize, 16 ); m_ReflectionTexture.name = "__MirrorReflection" + GetInstanceID(); m_ReflectionTexture.isPowerOfTwo = true; m_ReflectionTexture.hideFlags = HideFlags.DontSave; m_OldReflectionTextureSize = m_TextureSize; } // 相机反射 reflectionCamera = m_ReflectionCameras[currentCamera] as Camera; if( !reflectionCamera ) // catch both not-in-dictionary and in-dictionary-but-deleted-GO { GameObject go = new GameObject( "Mirror Refl Camera id" + GetInstanceID() + " for " + currentCamera.GetInstanceID(), typeof(Camera), typeof(Skybox) ); reflectionCamera = go.GetComponent<Camera>(); reflectionCamera.enabled = false; reflectionCamera.transform.position = transform.position; reflectionCamera.transform.rotation = transform.rotation; reflectionCamera.gameObject.AddComponent<FlareLayer>(); go.hideFlags = HideFlags.HideAndDontSave; m_ReflectionCameras[currentCamera] = reflectionCamera; } } // 扩展符号：返回-基于符号的1, 0或1 private static float sgn(float a) { if (a > 0.0f) return 1.0f; if (a < 0.0f) return -1.0f; return 0.0f; } //给定平面的位置/法线，在相机空间中计算平面。 private Vector4 CameraSpacePlane (Camera cam, Vector3 pos, Vector3 normal, float sideSign) { Vector3 offsetPos = pos + normal * m_ClipPlaneOffset; Matrix4x4 m = cam.worldToCameraMatrix; Vector3 cpos = m.MultiplyPoint( offsetPos ); Vector3 cnormal = m.MultiplyVector( normal ).normalized * sideSign; return new Vector4( cnormal.x, cnormal.y, cnormal.z, -Vector3.Dot(cpos,cnormal) ); } // 调整给定的投影矩阵，使近平面为给定的裁剪平面。 // 剪辑平面是在相机空间中给出的。参见游戏编程宝石5。 private static void CalculateObliqueMatrix (ref Matrix4x4 projection, Vector4 clipPlane) { Vector4 q = projection.inverse * new Vector4( sgn(clipPlane.x), sgn(clipPlane.y), 1.0f, 1.0f ); Vector4 c = clipPlane * (2.0F / (Vector4.Dot (clipPlane, q))); // 第三行=剪辑平面-第四行 projection[2] = c.x - projection[3]; projection[6] = c.y - projection[7]; projection[10] = c.z - projection[11]; projection[14] = c.w - projection[15]; } // 计算给定平面周围的反射矩阵。 private static void CalculateReflectionMatrix (ref Matrix4x4 reflectionMat, Vector4 plane) { reflectionMat.m00 = (1F - 2F*plane[0]*plane[0]); reflectionMat.m01 = ( - 2F*plane[0]*plane[1]); reflectionMat.m02 = ( - 2F*plane[0]*plane[2]); reflectionMat.m03 = ( - 2F*plane[3]*plane[0]); reflectionMat.m10 = ( - 2F*plane[1]*plane[0]); reflectionMat.m11 = (1F - 2F*plane[1]*plane[1]); reflectionMat.m12 = ( - 2F*plane[1]*plane[2]); reflectionMat.m13 = ( - 2F*plane[3]*plane[1]); reflectionMat.m20 = ( - 2F*plane[2]*plane[0]); reflectionMat.m21 = ( - 2F*plane[2]*plane[1]); reflectionMat.m22 = (1F - 2F*plane[2]*plane[2]); reflectionMat.m23 = ( - 2F*plane[3]*plane[2]); reflectionMat.m30 = 0F; reflectionMat.m31 = 0F; reflectionMat.m32 = 0F; reflectionMat.m33 = 1F; } } shader代码 Shader "FX/Mirror" { Properties { _MainTex ("Base (RGB)", 2D) = "white" {} _ReflectionTex ("Reflection", 2D) = "white" { TexGen ObjectLinear } } // 两张纹理卡片：完整的东西 Subshader { Pass { SetTexture[_MainTex] { combine texture } SetTexture[_ReflectionTex] { matrix [_ProjMatrix] combine texture * previous } } } // 后退：只是主纹理 Subshader { Pass { SetTexture [_MainTex] { combine texture } } } }