Unity图形学之Shader2.0 Blurning

1.屏幕后期特效：场景渲染完以后 在 添加一些特效

（1）引擎 渲染后最终的结构 是一张图片：OnRenderImage是脚本生命周期函数

Graphics.Blit(sourceTexture, desTexture, graphicsMat);

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class CameraMove : MonoBehaviour
{// Start is called before the first frame updatevoid Start(){graphicsMat = new Material(myShader);}// Update is called once per framevoid Update(){}public Shader myShader;private Material graphicsMat;//sourceTexture 相机在整个场景渲染完后传递给我们的图片  desTexture 更改以后得图片  存在这里，重新交给引擎重新渲染void OnRenderImage(RenderTexture sourceTexture, RenderTexture desTexture) {//指定一个Material 去渲染拦截的图片sourceTexture，最终输出新的desTextureGraphics.Blit(sourceTexture, desTexture, graphicsMat);}
}

（2）将图片 传递给 shader 进行 二次计算：

Shader "Hidden/GaoSi"
{Properties{_MainTex ("Texture", 2D) = "white" {}_Ambient("Ambient",float) = 0.001}SubShader{// No culling or depthCull Off ZWrite Off ZTest AlwaysPass{CGPROGRAM#pragma vertex vert#pragma fragment frag#include "UnityCG.cginc"struct appdata{float4 vertex : POSITION;float2 uv : TEXCOORD0;};struct v2f{float2 uv : TEXCOORD0;float4 vertex : SV_POSITION;};float _Ambient;v2f vert (appdata v){v2f o;o.vertex = UnityObjectToClipPos(v.vertex);o.uv = v.uv;return o;}sampler2D _MainTex;fixed4 frag (v2f i) : SV_Target{float2 tempUV = i.uv;//float ambient = _Ambient;fixed4 col = tex2D(_MainTex, tempUV);fixed4 col2 = tex2D(_MainTex, tempUV+float2(-_Ambient,0));fixed4 col3 = tex2D(_MainTex, tempUV+float2(0,-_Ambient));fixed4 col4 = tex2D(_MainTex, tempUV+float2(_Ambient,0));fixed4 col5 = tex2D(_MainTex, tempUV+float2(0,_Ambient));col = (col+col2+col3+col4+col5) / 5.0;// just invert the colors//col.rgb = 1 - col.rgb;return col;}ENDCG}}
}