unity3d 实现残影特效

using UnityEngine;

using System.Collections;

using System.Collections.Generic;

//[ExecuteInEditMode]

[RequireComponent(typeof(Camera))]
public class TestMRT : MonoBehaviour
{
public Material testMRTMaterial = null;
public RenderTexture[] mrtTex   = new RenderTexture[2];
public RenderTexture[] TextureA = new RenderTexture[2];
RenderBuffer[] mrtRB = new RenderBuffer[2];

public Camera effectCame;

public Texture texture0;
public Texture texture1;
public RenderTexture sourTexture;
public RenderTexture canYanTexture;
public RenderTexture curTexture;
public Material CreateCanYinMaterial;
void Start()
{
TextureA[0] = new RenderTexture(Screen.width, Screen.height, 24, RenderTextureFormat.ARGB32);
TextureA[1] = new RenderTexture(Screen.width, Screen.height, 24, RenderTextureFormat.ARGB32);

Shader testMRT = Shader.Find("Custom/TestMRT");
if (testMRT.isSupported)
testMRTMaterial = new Material(testMRT);
else
return;
Shader CanyanCreat = Shader.Find("Custom/CanyanCreat");
if (CanyanCreat.isSupported)
CreateCanYinMaterial = new Material(CanyanCreat);
else
return;
StartCoroutine(ShowEffect());
}

void OnRenderImage(RenderTexture source, RenderTexture destination)
{
sourTexture = source;
//Graphics.Blit(sourTexture, source, testMRTMaterial, 0);
if (!testMRTMaterial.shader.isSupported)
{
Graphics.Blit(source, destination);
return;

}

//Show the result
testMRTMaterial.SetTexture("_Tex0", sourTexture);
testMRTMaterial.SetTexture("_Tex1", curTexture);
//Graphics.Blit(curTexture, destination, testMRTMaterial, 2);
Graphics.Blit(null, destination, testMRTMaterial, 2);

}

Dictionary<Renderer, Material[]> rendToMat = new Dictionary<Renderer, Material[]>();

void Clear(RenderTexture destTexture)
{
Graphics.SetRenderTarget(destTexture);
GL.PushMatrix();
GL.Clear(true, true, Color.white);
GL.PopMatrix();
}

void InitCanYanTexture()
{
playRoot = GameObject.Find("Players").transform;
Transform[] chs = playRoot.GetComponentsInChildren<Transform>();
int effectLayer = LayerMask.NameToLayer("ImageEffect");
for (int i = 0, iMax = chs.Length; i < iMax; i++)
{
chs[i].gameObject.layer = effectLayer;
Renderer red = chs[i].GetComponent<Renderer>();
if (red != null)
{
if (red.sharedMaterial.shader.name == "Toon/Basic" ||
red.gameObject.name == "m_battle_box01")
{
Material newMt = GameObject.Instantiate(CreateCanYinMaterial) as Material;
newMt.mainTexture = red.sharedMaterial.mainTexture;
rendToMat.Add(red, new Material[] { red.sharedMaterial, newMt });
}
else
Debuger.Log(red.sharedMaterial.shader.name);
}

}
effectCame.cullingMask = 1 << effectLayer;
canYanTexture = new RenderTexture(Screen.width, Screen.height, 24, RenderTextureFormat.ARGB32);
effectCame.targetTexture = canYanTexture;
}
void CreateCanYanTexture()
{
int colorId = Shader.PropertyToID("_Color");
Shader sd = CreateCanYinMaterial.shader;
float i = 0;
foreach (KeyValuePair<Renderer, Material[]> pair in rendToMat)
{
i += 1f;
Renderer rd = pair.Key;
rd.sharedMaterial = rendToMat[rd][1];
rd.sharedMaterial.SetColor(colorId, new Color(0, 0, 1,0.7f+0.1f*i));
}
//GL.Clear(true, true, Color.clear);
effectCame.Render();
foreach (KeyValuePair<Renderer, Material[]> pair in rendToMat)
{
Renderer rd = pair.Key;
rd.sharedMaterial = rendToMat[rd][0];
}

}
private Transform playRoot;
IEnumerator ShowEffect()
{
InitCanYanTexture();
int ii = 0;
while(true)
{
CreateCanYanTexture();
yield return new WaitForSeconds(0.01f);
int a = ii % 2;//0;//
int b = ++ii % 2;//1;//
curTexture = TextureA[a];
Graphics.SetRenderTarget(curTexture);
GL.Clear(false, false, Color.clear);
testMRTMaterial.SetTexture("_Tex0", sourTexture);
testMRTMaterial.SetTexture("_Tex1", TextureA[b]);
testMRTMaterial.SetTexture("_MainTex", canYanTexture);

GL.PushMatrix();

GL.LoadOrtho();

testMRTMaterial.SetPass(1);     //Pass 0 outputs 2 render textures.

GL.Begin(GL.QUADS);

GL.TexCoord2(0.0f, 0); GL.Vertex3(0.0f, 0.0f, 0.1f);

GL.TexCoord2(1.0f, 0); GL.Vertex3(1.0f, 0.0f, 0.1f);

GL.TexCoord2(1.0f, 1); GL.Vertex3(1.0f, 1.0f, 0.1f);

GL.TexCoord2(0.0f, 1); GL.Vertex3(0.0f, 1.0f, 0.1f);

GL.End();

GL.PopMatrix();

}
}
}

Shader "Custom/CanyanCreat" {
Properties {
_MainTex ("", 2D) = "" {}
_Color ("Main Color", Color) = (1,1,1,1)
}

CGINCLUDE
#include "UnityCG.cginc"
struct v2f {
float4 pos : POSITION;
float2 uv : TEXCOORD0;
};

uniform float4 _Color;
sampler2D _MainTex;

v2f vert( appdata_img v )
{
v2f o;
o.pos = mul(UNITY_MATRIX_MVP, v.vertex);
o.uv = v.texcoord.xy;
return o;
}
float4 fragCanYenCreate(v2f pixelData) : COLOR0
{
float4 col1 = tex2D(_MainTex, pixelData.uv);//上一帧的累加图
//float4 col = _Color.a*(col1*0.8f+_Color*(1 - col1.a));
float4 col = _Color+col1;
col.a = _Color.a;//1.0f;//0.1f;
return col;
}
ENDCG

Subshader {
Pass {
ZTest Always Cull Off ZWrite Off
Fog { Mode off }
//Blend one zero
CGPROGRAM
#pragma glsl
#pragma fragmentoption ARB_precision_hint_fastest
#pragma vertex vert
#pragma fragment fragCanYenCreate
#pragma target 3.0

ENDCG
}

}

Fallback off

}

Shader "Custom/TestMRT" {
Properties {
_MainTex ("", 2D) = "" {}
}

CGINCLUDE
#include "UnityCG.cginc"
struct v2f {
float4 pos : POSITION;
float2 uv : TEXCOORD0;
};

struct PixelOutput {
float4 col0 : COLOR0;
float4 col1 : COLOR1;
};

sampler2D _MainTex;
sampler2D _Tex0;
sampler2D _Tex1;
v2f vert( appdata_img v )
{
v2f o;
o.pos = mul(UNITY_MATRIX_MVP, v.vertex);
o.uv = v.texcoord.xy;
return o;
}
//可以返回多个颜色,对应的
//public static void SetRenderTarget(RenderBuffer[] colorBuffers, RenderBuffer depthBuffer); 可用多个buff接受
//Graphics.SetRenderTarget(mrtRB, mrtTex[0].depthBuffer);
PixelOutput fragTestMRT(v2f pixelData)
{
PixelOutput o;
o.col0 = float4(1.0f, 0.0f, 0.0f, 1.0f);
o.col1 = float4(0.0f, 1.0f, 0.0f, 1.0f);
return o;
}

float4 fragCanYenAdd(v2f pixelData) : COLOR0
{
//float4 col0 = tex2D(_Tex0, pixelData.uv);//当前场景原图
float4 col1 = tex2D(_Tex1, pixelData.uv);//上一帧的累加残影图
float4 colM = tex2D(_MainTex, pixelData.uv);//当前场景新的残影图原图,a通道存放 衰减系数这样就可以控制 残影的长度
float4 col;
//col = colM + col1*(1 - colM)*0.9f;//通过*0.9f的衰减系数，控制残影销毁
col.rgb = colM.rbg + col1.rgb*(1 - colM.rgb)*0.9;
//col.a = colM.a + col1.a;
return col;
}
float4 fragCanYenBind(v2f pixelData) : COLOR0
{
float2 uuv = float2(pixelData.uv.x,1- pixelData.uv.y);
float4 col0 = tex2D(_Tex0, uuv);//当前场景原图
float4 col1 = tex2D(_Tex1, pixelData.uv);//上一帧的累加残影图

float4 col;
col = col0 + col1*(1 - col0.a);
return col;
}
ENDCG

Subshader {

Pass {
ZTest Always Cull Off ZWrite Off
Fog { Mode off }

CGPROGRAM
#pragma glsl
#pragma fragmentoption ARB_precision_hint_fastest
#pragma vertex vert
#pragma fragment fragTestMRT
#pragma target 3.0
ENDCG
}
Pass {

ZTest Always Cull Off ZWrite Off
Fog { Mode off }
//Blend one zero
CGPROGRAM
#pragma glsl
#pragma fragmentoption ARB_precision_hint_fastest
#pragma vertex vert
#pragma fragment fragCanYenAdd
#pragma target 3.0
ENDCG
}
Pass {

ZTest Always Cull Off ZWrite Off
Fog { Mode off }
//Blend one zero
CGPROGRAM
#pragma glsl
#pragma fragmentoption ARB_precision_hint_fastest
#pragma vertex vert
#pragma fragment fragCanYenBind
#pragma target 3.0
ENDCG
}
}

Fallback off

}

using UnityEngine;

using System.Collections;

using System.Collections.Generic;

//[ExecuteInEditMode]

[RequireComponent(typeof(Camera))]
public class TestMRT : MonoBehaviour
{
public Material testMRTMaterial = null;
public RenderTexture[] mrtTex   = new RenderTexture[2];
public RenderTexture[] TextureA = new RenderTexture[2];
RenderBuffer[] mrtRB = new RenderBuffer[2];

public Camera effectCame;

public Texture texture0;
public Texture texture1;
public RenderTexture sourTexture;
public RenderTexture canYanTexture;
public RenderTexture curTexture;
public Material CreateCanYinMaterial;
void Start()
{
TextureA[0] = new RenderTexture(Screen.width, Screen.height, 24, RenderTextureFormat.ARGB32);
TextureA[1] = new RenderTexture(Screen.width, Screen.height, 24, RenderTextureFormat.ARGB32);

Shader testMRT = Shader.Find("Custom/TestMRT");
if (testMRT.isSupported)
testMRTMaterial = new Material(testMRT);
else
return;
Shader CanyanCreat = Shader.Find("Custom/CanyanCreat");
if (CanyanCreat.isSupported)
CreateCanYinMaterial = new Material(CanyanCreat);
else
return;
StartCoroutine(ShowEffect());
}

void OnRenderImage(RenderTexture source, RenderTexture destination)
{
sourTexture = source;
//Graphics.Blit(sourTexture, source, testMRTMaterial, 0);
if (!testMRTMaterial.shader.isSupported)
{
Graphics.Blit(source, destination);
return;

}

//Show the result
testMRTMaterial.SetTexture("_Tex0", sourTexture);
testMRTMaterial.SetTexture("_Tex1", curTexture);
//Graphics.Blit(curTexture, destination, testMRTMaterial, 2);
Graphics.Blit(null, destination, testMRTMaterial, 2);

}

Dictionary<Renderer, Material[]> rendToMat = new Dictionary<Renderer, Material[]>();

void Clear(RenderTexture destTexture)
{
Graphics.SetRenderTarget(destTexture);
GL.PushMatrix();
GL.Clear(true, true, Color.white);
GL.PopMatrix();
}

void InitCanYanTexture()
{
//effectCame;
GameObject cameObj = new GameObject("effectCame");
cameObj.transform.parent = Camera.main.gameObject.transform;
cameObj.transform.localPosition = Vector3.zero;
effectCame = cameObj.AddComponent<Camera>();
effectCame.CopyFrom(Camera.main);
effectCame.clearFlags = CameraClearFlags.SolidColor;
effectCame.backgroundColor = Color.clear;
effectCame.enabled = false;

if (playRoot == null)
if (GameObject.Find("Players"))
playRoot = GameObject.Find("Players").transform;
if (playRoot == null)
playRoot = GameObject.Find("GameOnly").transform.FindChild("SceneParent/PlayerRoot");

Transform[] chs = playRoot.GetComponentsInChildren<Transform>();
int effectLayer = LayerMask.NameToLayer("ImageEffect");
for (int i = 0, iMax = chs.Length; i < iMax; i++)
{
chs[i].gameObject.layer = effectLayer;
Renderer red = chs[i].GetComponent<Renderer>();
if (red != null)
{
if (red.sharedMaterial.shader.name == "Toon/Basic" ||
red.gameObject.name == "m_battle_box01"||
red is SkinnedMeshRenderer)
{
Material newMt = GameObject.Instantiate(CreateCanYinMaterial) as Material;
newMt.mainTexture = red.sharedMaterial.mainTexture;
rendToMat.Add(red, new Material[] { red.sharedMaterial, newMt });
}
else
Debuger.Log(red.sharedMaterial.shader.name);
}

}
effectCame.cullingMask = 1 << effectLayer;
canYanTexture = new RenderTexture(Screen.width, Screen.height, 24, RenderTextureFormat.ARGB32);
effectCame.targetTexture = canYanTexture;
camePos = Camera.main.transform.position;
tarPos = tarObj.position;
ccpos = Camera.main.transform.position - tarObj.position;
}

void CreateCanYanTexture()
{
int colorId = Shader.PropertyToID("_Color");
Shader sd = CreateCanYinMaterial.shader;
float i = 0;
foreach (KeyValuePair<Renderer, Material[]> pair in rendToMat)
{
i += 1f;
Renderer rd = pair.Key;
rd.sharedMaterial = rendToMat[rd][1];
rd.sharedMaterial.SetColor(colorId, new Color(0, 0, 1,0.7f+0.1f*i));
}
//GL.Clear(true, true, Color.clear);
effectCame.Render();
foreach (KeyValuePair<Renderer, Material[]> pair in rendToMat)
{
Renderer rd = pair.Key;
rd.sharedMaterial = rendToMat[rd][0];
}

}
public Transform tarObj;
Vector3 camePos = Vector3.zero;
Vector3 tarPos = Vector3.zero;

Vector3 ccpos = Vector3.zero;
void Update()
{
//Camera.main.transform.position = tarObj.position + ccpos;
}
private Transform playRoot;
IEnumerator ShowEffect()
{
InitCanYanTexture();
int ii = 0;
Vector4 cameMove = Vector4.zero;

while(true)
{
CreateCanYanTexture();

if (camePos != Camera.main.transform.position)
{
Vector3 newTarPos = tarObj.position;
Vector2 pm1 = effectCame.WorldToScreenPoint(tarPos);
Vector2 pm2 = effectCame.WorldToScreenPoint(newTarPos);
tarPos = newTarPos;
camePos = effectCame.transform.position;
cameMove = pm2 - pm1;
}
cameMove.z = Screen.width;
cameMove.w = Screen.height;

yield return new WaitForSeconds(0.01f);
int a = ii % 2;//0;//
int b = ++ii % 2;//1;//
curTexture = TextureA[a];
Graphics.SetRenderTarget(curTexture);
GL.Clear(false, false, Color.clear);
GL.PushMatrix();

GL.LoadOrtho();
testMRTMaterial.SetTexture("_Tex0", sourTexture);
testMRTMaterial.SetTexture("_Tex1", TextureA[b]);
testMRTMaterial.SetTexture("_MainTex", canYanTexture);
testMRTMaterial.SetVector("_cameMove", cameMove);

testMRTMaterial.SetPass(1);     //Pass 0 outputs 2 render textures.

GL.Begin(GL.QUADS);

GL.TexCoord2(0.0f, 0); GL.Vertex3(0.0f, 0.0f, 0.1f);

GL.TexCoord2(1.0f, 0); GL.Vertex3(1.0f, 0.0f, 0.1f);

GL.TexCoord2(1.0f, 1); GL.Vertex3(1.0f, 1.0f, 0.1f);

GL.TexCoord2(0.0f, 1); GL.Vertex3(0.0f, 1.0f, 0.1f);

GL.End();

GL.PopMatrix();

}
}
}