Unity3d 镜面折射 vertex and frag Shader源代码

Unity3d 镜面折射 

网上能找到的基本上是固定管道或表面渲染的shader。

特此翻译为顶点、片段渲染的Shader，

本源代码仅仅涉及shader与cs部分，

请自行下载NGUI 

unity3d 版本号:v4.3.1

RefractionMirror.cs

using UnityEngine;
using System.Collections;
using System;

/// <summary>
/// 镜面折射效果
/// </summary>
[AddComponentMenu("GameCore/Effect/Refraction/Mirror")]
[ExecuteInEditMode]
public class RefractionMirror : MonoBehaviour
{
    public bool DisablePixelLights = true;
    public int TextureSize = 512;
    public float ClipPlaneOffset = 0;
    public LayerMask ReflectLayers = -1;

    private Hashtable _RefractionCameras = new Hashtable(); // Camera -> Camera table
    private RenderTexture _RefractionTexture = null;
    private int _OldRefractionTextureSize = 0;

    private static bool _InsideRendering = false;

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

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

        // Safeguard from recursive Refractions.
        if (_InsideRendering)
            return;
        _InsideRendering = true;

        Camera RefractionCamera;
        CreateMirrorObjects(cam, out RefractionCamera);

        // find out the Refraction plane: position and normal in world space
        Vector3 pos = transform.position;
        Vector3 normal = transform.up;
        // Optionally disable pixel lights for Refraction
        int oldPixelLightCount = QualitySettings.pixelLightCount;
        if (DisablePixelLights)
            QualitySettings.pixelLightCount = 0;

        CoreTool.CloneCameraModes(cam, RefractionCamera);

        RefractionCamera.cullingMask = ~(1 << 4) & ReflectLayers.value; // never render water layer
        RefractionCamera.targetTexture = _RefractionTexture;
        RefractionCamera.transform.position = cam.transform.position;
        RefractionCamera.transform.eulerAngles = cam.transform.eulerAngles;
        RefractionCamera.Render();
        Material[] materials = renderer.sharedMaterials;
        foreach (Material mat in materials)
        {
            if (mat.HasProperty("_RefractionTex"))
                mat.SetTexture("_RefractionTex", _RefractionTexture);
        }

        // Set matrix on the shader that transforms UVs from object space into screen
        // space. We want to just project Refraction 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 (DisablePixelLights)
            QualitySettings.pixelLightCount = oldPixelLightCount;
        _InsideRendering = false;
    }

    // Cleanup all the objects we possibly have created
    void OnDisable()
    {
        if (_RefractionTexture)
        {
            DestroyImmediate(_RefractionTexture);
            _RefractionTexture = null;
        }
        foreach (DictionaryEntry kvp in _RefractionCameras)
            DestroyImmediate(((Camera)kvp.Value).gameObject);
        _RefractionCameras.Clear();
    }

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

        // Refraction render texture
        if (!_RefractionTexture || _OldRefractionTextureSize != TextureSize)
        {
            if (_RefractionTexture)
                DestroyImmediate(_RefractionTexture);
            _RefractionTexture = new RenderTexture(TextureSize, TextureSize, 0);
            _RefractionTexture.name = "__MirrorRefraction" + GetInstanceID();
            _RefractionTexture.isPowerOfTwo = true;
            _RefractionTexture.hideFlags = HideFlags.DontSave;
            _RefractionTexture.antiAliasing = 4;
            _RefractionTexture.anisoLevel = 0;
            _OldRefractionTextureSize = TextureSize;
        }

        // Camera for Refraction
        RefractionCamera = _RefractionCameras[currentCamera] as Camera;
        if (!RefractionCamera) // 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));
            RefractionCamera = go.camera;
            RefractionCamera.enabled = false;
            RefractionCamera.transform.position = transform.position;
            RefractionCamera.transform.rotation = transform.rotation;
            RefractionCamera.gameObject.AddComponent("FlareLayer");
            go.hideFlags = HideFlags.HideAndDontSave;
            _RefractionCameras[currentCamera] = RefractionCamera;
        }
    }
}

shader

Shader "GameCore/Mobile/Refraction/Mirror"
{
    Properties {
        _RefractionTex ("Refraction", 2D) = "white" {TexGen ObjectLinear }
		_RefractionColor("Color",Color) = (1,1,1,1)
	}
	SubShader {
        Tags {
            "RenderType"="Opaque"}
		LOD 100
		Pass {
            CGPROGRAM
			#pragma vertex vert
			#pragma fragment frag
			#include "UnityCG.cginc"

			uniform float4x4 _ProjMatrix;
            uniform sampler2D _RefractionTex;
            float4 _RefractionColor;
            struct outvertex {
                float4 pos : SV_POSITION;
                float3 uv : TEXCOORD0;
                float4 posProj;
            };
            outvertex vert(appdata_tan v) {
                outvertex o;
                o.pos = mul (UNITY_MATRIX_MVP,v.vertex);
                o.posProj = mul(_ProjMatrix, v.vertex);
				return o;
            }
			float4 frag(outvertex i) : COLOR {
				half4 reflcol = tex2D(_RefractionTex,float2(i.posProj) / i.posProj.w);
                return reflcol*_RefractionColor;
            }
			ENDCG
		}
	}
}

Shader "GameCore/Refraction/Mirror"
{
    Properties {
        _RefractionTex ("Refraction ", 2D) = "white" {TexGen ObjectLinear }
		_RefractionColor("Color",Color) = (1,1,1,1)
	}
	SubShader {
        Tags {
            "RenderType"="Opaque"}
		LOD 100
		Pass {
            CGPROGRAM
			#pragma vertex vert
			#pragma fragment frag
			#include "UnityCG.cginc"

			uniform float4x4 _ProjMatrix;
            uniform sampler2D _RefractionTex;
            float4 _RefractionColor;
            struct outvertex {
                float4 pos : SV_POSITION;
                float3 uv : TEXCOORD0;
            };
            outvertex vert(appdata_tan v) {
                outvertex o;
                o.pos = mul (UNITY_MATRIX_MVP,v.vertex);
                float3 viewDir = ObjSpaceViewDir(v.vertex);
				o.uv = mul(_ProjMatrix,float4(viewDir,0));
				return o;
            }

			float4 frag(outvertex i) : COLOR {
                half4 reflcol = tex2Dproj(_RefractionTex,i.uv);
                return reflcol*_RefractionColor;
            }
			ENDCG
		}
	}
}