∮紫∈寒§ 发表于 2012-12-3 09:57

unity3D中镜面反射

新建一个shaderShader "FX/Mirror Reflection" {
Properties {
_MainTex ("Base (RGB)", 2D) = "white" {}
_ReflectionTex ("Reflection", 2D) = "white" { TexGen ObjectLinear }
}

// two texture cards: full thing
Subshader {
Pass {
SetTexture { combine texture }
SetTexture { matrix combine texture * previous }
}
}

// fallback: just main texture
Subshader {
Pass {
SetTexture { combine texture }
}
}

}新建一个脚本using UnityEngine;
using System.Collections;

// This is in fact just the Water script from Pro Standard Assets,
// just with refraction stuff removed.

// Make mirror live-update even when not in play mode
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(); // Camera -> Camera table

    private RenderTexture m_ReflectionTexture = null;
    private int m_OldReflectionTextureSize = 0;

    private static bool s_InsideRendering = false;

    // This is called when it's known that the object will be rendered by some
    // camera. We render reflections and do other updates here.
    // Because the script executes in edit mode, reflections for the scene view
    // camera will just work!
    public void OnWillRenderObject()
    {
      if (!enabled || !renderer || !renderer.sharedMaterial || !renderer.enabled)
            return;

      Camera cam = Camera.current;
      if (!cam)
            return;

      // Safeguard from recursive reflections.
      if (s_InsideRendering)
            return;
      s_InsideRendering = true;

      Camera reflectionCamera;
      CreateMirrorObjects(cam, out reflectionCamera);

      // find out the reflection plane: position and normal in world space
      Vector3 pos = transform.position;
      Vector3 normal = transform.up;

      // Optionally disable pixel lights for reflection
      int oldPixelLightCount = QualitySettings.pixelLightCount;
      if (m_DisablePixelLights)
            QualitySettings.pixelLightCount = 0;

      UpdateCameraModes(cam, reflectionCamera);

      // Render reflection
      // Reflect camera around reflection plane
      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;

      // Setup oblique projection matrix so that near plane is our reflection
      // plane. This way we clip everything below/above it for free.
      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; // never render water layer
      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 = renderer.sharedMaterials;
      foreach (Material mat in materials)
      {
            if (mat.HasProperty("_ReflectionTex"))
                mat.SetTexture("_ReflectionTex", m_ReflectionTexture);
      }

      // Set matrix on the shader that transforms UVs from object space into screen
      // space. We want to just project reflection texture on screen.
      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);
      }

      // Restore pixel light count
      if (m_DisablePixelLights)
            QualitySettings.pixelLightCount = oldPixelLightCount;

      s_InsideRendering = false;
    }


    // Cleanup all the objects we possibly have created
    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;
      // set camera to clear the same way as current camera
      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;
            }
      }
      // update other values to match current camera.
      // even if we are supplying custom camera&projection matrices,
      // some of values are used elsewhere (e.g. skybox uses far plane)
      dest.farClipPlane = src.farClipPlane;
      dest.nearClipPlane = src.nearClipPlane;
      dest.orthographic = src.orthographic;
      dest.fieldOfView = src.fieldOfView;
      dest.aspect = src.aspect;
      dest.orthographicSize = src.orthographicSize;
    }

    // On-demand create any objects we need
    private void CreateMirrorObjects(Camera currentCamera, out Camera reflectionCamera)
    {
      reflectionCamera = null;

      // Reflection render texture
      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;
      }

      // Camera for reflection
      reflectionCamera = m_ReflectionCameras 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.camera;
            reflectionCamera.enabled = false;
            reflectionCamera.transform.position = transform.position;
            reflectionCamera.transform.rotation = transform.rotation;
            reflectionCamera.gameObject.AddComponent("FlareLayer");
            go.hideFlags = HideFlags.HideAndDontSave;
            m_ReflectionCameras = reflectionCamera;
      }
    }

    // Extended sign: returns -1, 0 or 1 based on sign of a
    private static float sgn(float a)
    {
      if (a > 0.0f) return 1.0f;
      if (a < 0.0f) return -1.0f;
      return 0.0f;
    }

    // Given position/normal of the plane, calculates plane in camera space.
    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));
    }

    // Adjusts the given projection matrix so that near plane is the given clipPlane
    // clipPlane is given in camera space. See article in Game Programming Gems 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)));
      // third row = clip plane - fourth row
      projection = c.x - projection;
      projection = c.y - projection;
      projection = c.z - projection;
      projection = c.w - projection;
    }

    // Calculates reflection matrix around the given plane
    private static void CalculateReflectionMatrix(ref Matrix4x4 reflectionMat, Vector4 plane)
    {
      reflectionMat.m00 = (1F - 2F * pla


ne * plane);
      reflectionMat.m01 = (-2F * plane * plane);
      reflectionMat.m02 = (-2F * plane * plane);
      reflectionMat.m03 = (-2F * plane * plane);

      reflectionMat.m10 = (-2F * plane * plane);
      reflectionMat.m11 = (1F - 2F * plane * plane);
      reflectionMat.m12 = (-2F * plane * plane);
      reflectionMat.m13 = (-2F * plane * plane);

      reflectionMat.m20 = (-2F * plane * plane);
      reflectionMat.m21 = (-2F * plane * plane);
      reflectionMat.m22 = (1F - 2F * plane * plane);
      reflectionMat.m23 = (-2F * plane * plane);

      reflectionMat.m30 = 0F;
      reflectionMat.m31 = 0F;
      reflectionMat.m32 = 0F;
      reflectionMat.m33 = 1F;
    }
}如图把这两个赋在物体身上




大将军 发表于 2012-12-3 14:10

好牛逼的脚本收藏了{:5_412:}

∮紫∈寒§ 发表于 2012-12-3 15:01

顶顶顶顶{:5_397:}{:5_397:}{:5_397:}{:5_397:}{:5_397:}{:5_397:}

qarluqd25 发表于 2012-12-13 13:07

谢谢分享学习学习

go369 发表于 2012-12-13 15:56

回复看图咯

xenomaya 发表于 2013-7-26 18:45

谢谢分享学习学习

为你等待 发表于 2014-5-26 10:25


膜拜中。。。。{:soso__7524161091986203637_5:}

jstones 发表于 2017-3-1 08:37

楼主是超人

fangguanya 发表于 2017-3-1 08:55

顶顶多好

你微笑时好美丶 发表于 2017-3-1 08:45

真心顶
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