查看: 3993|回复: 85

[渲染] Unity3D一个镜面反射的材质

[复制链接]

40

主题

16

听众

230

积分

小学生

Rank: 2

升级   10%

发表于 2012-8-11 11:13 |显示全部楼层
共享资源获取更多积分!share your resources get more credits!

  1. Shader:


  2. Shader "FX/Mirror Reflection" {
  3. Properties {
  4.     _MainTex ("Base (RGB)", 2D) = "white" {}
  5.     _ReflectionTex ("Reflection", 2D) = "white" { TexGen ObjectLinear }
  6. }

  7. // two texture cards: full thing
  8. Subshader {
  9.     Pass {
  10.         SetTexture[_MainTex] { combine texture }
  11.         SetTexture[_ReflectionTex] { matrix [_ProjMatrix] combine texture * previous }
  12.     }
  13. }

  14. // fallback: just main texture
  15. Subshader {
  16.     Pass {
  17.         SetTexture [_MainTex] { combine texture }
  18.     }
  19. }

  20. }
复制代码
[code=csharp]C#


using UnityEngine;
using System.Collections;

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

[ExecuteInEditMode] // 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&#91;&#93; 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&#91;currentCamera&#93; 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&#91;currentCamera&#93; = 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&#91;2&#93; = c.x - projection&#91;3&#93;;
        projection&#91;6&#93; = c.y - projection&#91;7&#93;;
        projection&#91;10&#93; = c.z - projection&#91;11&#93;;
        projection&#91;14&#93; = c.w - projection&#91;15&#93;;
    }

    // Calculates reflection matrix around the given plane
    private static void CalculateReflectionMatrix (ref Matrix4x4 reflectionMat, Vector4 plane)
    {
        reflectionMat.m00 = (1F - 2F*plane&#91;0&#93;*plane&#91;0&#93;);
        reflectionMat.m01 = (   - 2F*plane&#91;0&#93;*plane&#91;1&#93;);
        reflectionMat.m02 = (   - 2F*plane&#91;0&#93;*plane&#91;2&#93;);
        reflectionMat.m03 = (   - 2F*plane&#91;3&#93;*plane&#91;0&#93;);

        reflectionMat.m10 = (   - 2F*plane&#91;1&#93;*plane&#91;0&#93;);
        reflectionMat.m11 = (1F - 2F*plane&#91;1&#93;*plane&#91;1&#93;);
        reflectionMat.m12 = (   - 2F*plane&#91;1&#93;*plane&#91;2&#93;);
        reflectionMat.m13 = (   - 2F*plane&#91;3&#93;*plane&#91;1&#93;);
   
        reflectionMat.m20 = (   - 2F*plane&#91;2&#93;*plane&#91;0&#93;);
        reflectionMat.m21 = (   - 2F*plane&#91;2&#93;*plane&#91;1&#93;);
        reflectionMat.m22 = (1F - 2F*plane&#91;2&#93;*plane&#91;2&#93;);
        reflectionMat.m23 = (   - 2F*plane&#91;3&#93;*plane&#91;2&#93;);

        reflectionMat.m30 = 0F;
        reflectionMat.m31 = 0F;
        reflectionMat.m32 = 0F;
        reflectionMat.m33 = 1F;
    }
}[/code]

楼主热帖
该会员没有填写今日想说内容.

0

主题

12

听众

204

积分

小学生

Rank: 2

升级   1.33%

发表于 2017-2-28 19:44 |显示全部楼层
很不错
回复

使用道具 举报

0

主题

12

听众

200

积分

小学生

Rank: 2

升级   0%

发表于 2017-2-28 19:46 |显示全部楼层
楼主是超人
回复

使用道具 举报

0

主题

12

听众

203

积分

小学生

Rank: 2

升级   1%

发表于 2017-2-28 19:03 |显示全部楼层
顶顶多好
回复

使用道具 举报

0

主题

12

听众

203

积分

小学生

Rank: 2

升级   1%

发表于 2017-2-28 19:33 |显示全部楼层
真心顶
回复

使用道具 举报

0

主题

13

听众

205

积分

小学生

Rank: 2

升级   1.67%

发表于 2017-2-28 18:57 |显示全部楼层
难得一见的好帖
回复

使用道具 举报

0

主题

12

听众

202

积分

小学生

Rank: 2

升级   0.67%

发表于 2017-3-1 09:45 |显示全部楼层
很不错
回复

使用道具 举报

0

主题

12

听众

203

积分

小学生

Rank: 2

升级   1%

发表于 2017-3-1 10:09 |显示全部楼层
顶顶多好
回复

使用道具 举报

0

主题

12

听众

201

积分

小学生

Rank: 2

升级   0.33%

发表于 2017-3-1 09:23 |显示全部楼层
难得一见的好帖
回复

使用道具 举报

0

主题

12

听众

200

积分

小学生

Rank: 2

升级   0%

发表于 2017-3-1 10:00 |显示全部楼层
说的非常好
回复

使用道具 举报

温馨提示:求助请到“Unity技术讨论”版块中发帖,便于集中解决!
您需要登录后才可以回帖 登录 | 立即注册

懒人模式:

关闭

站长推荐 上一条 /1 下一条

Unity3D游戏开发联盟(资源共享平台) -Unity3D,Unreal ( 粤ICP备20003399号-2 )

GMT+8, 2020-5-31 01:36 , Processed in 0.060274 second(s), 37 queries .