Unity全屏模糊

先上效果，左边模糊

其实用的是Unity Stard Effect里的资源，一个脚本一个shader

//脚本代码

using UnityEngine;
using System.Collections;

[ExecuteInEditMode]
[AddComponentMenu("Image Effects/Blur/Blur")]
public class BlurEffect : MonoBehaviour
{    
    /// Blur iterations - larger number means more blur.
    public int iterations = 3;
    
    /// Blur spread for each iteration. Lower values
    /// give better looking blur, but require more iterations to
    /// get large blurs. Value is usually between 0.5 and 1.0.
    public float blurSpread = 0.6f;
    
    
    // --------------------------------------------------------
    // The blur iteration shader.
    // Basically it just takes 4 texture samples and averages them.
    // By applying it repeatedly and spreading out sample locations
    // we get a Gaussian blur approximation.
     
    public Shader blurShader = null;    

    //private static string blurMatString =

    static Material m_Material = null;
    protected Material material {
        get {
            if (m_Material == null) {
                m_Material = new Material(blurShader);
                m_Material.hideFlags = HideFlags.DontSave;
            }
            return m_Material;
        } 
    }
    
    protected void OnDisable() {
        if( m_Material ) {
            DestroyImmediate( m_Material );
        }
    }    
    
    // --------------------------------------------------------
    
    protected void Start()
    {
        // Disable if we don't support image effects
        if (!SystemInfo.supportsImageEffects) {
            enabled = false;
            return;
        }
        // Disable if the shader can't run on the users graphics card
        if (!blurShader || !material.shader.isSupported) {
            enabled = false;
            return;
        }
    }
    
    // Performs one blur iteration.
    public void FourTapCone (RenderTexture source, RenderTexture dest, int iteration)
    {
        float off = 0.5f + iteration*blurSpread;
        Graphics.BlitMultiTap (source, dest, material,
            new Vector2(-off, -off),
            new Vector2(-off,  off),
            new Vector2( off,  off),
            new Vector2( off, -off)
        );
    }
    
    // Downsamples the texture to a quarter resolution.
    private void DownSample4x (RenderTexture source, RenderTexture dest)
    {
        float off = 1.0f;
        Graphics.BlitMultiTap (source, dest, material,
            new Vector2(-off, -off),
            new Vector2(-off,  off),
            new Vector2( off,  off),
            new Vector2( off, -off)
        );
    }
    
    // Called by the camera to apply the image effect
    void OnRenderImage (RenderTexture source, RenderTexture destination) {        
        int rtW = source.width/4;
        int rtH = source.height/4;
        RenderTexture buffer = RenderTexture.GetTemporary(rtW, rtH, 0);
        
        // Copy source to the 4x4 smaller texture.
        DownSample4x (source, buffer);
        
        // Blur the small texture
        for(int i = 0; i < iterations; i++)
        {
            RenderTexture buffer2 = RenderTexture.GetTemporary(rtW, rtH, 0);
            FourTapCone (buffer, buffer2, i);
            RenderTexture.ReleaseTemporary(buffer);
            buffer = buffer2;
        }
        Graphics.Blit(buffer, destination);
        
        RenderTexture.ReleaseTemporary(buffer);
    }    
}

//shader

// electricity/lightning shader
// pixel shader 2.0 based rendering of electric spark
// by Ori Hanegby
// Free for any kind of use.


Shader "FX/Lightning" {
Properties {
    _SparkDist  ("Spark Distribution", range(-1,1)) = 0
    _MainTex ("MainTex (RGB)", 2D) = "white" {}
    _Noise ("Noise", 2D) = "noise" {}    
    _StartSeed ("StartSeed", Float) = 0
    _SparkMag ("Spark Magnitude" , range(1,100)) = 1
    _SparkWidth ("Spark Width" , range(0.001,0.499)) = 0.25
}

Category {

    // We must be transparent, so other objects are drawn before this one.
    Tags { "Queue"="Transparent" }


    SubShader {        
         
         // Main pass: Take the texture grabbed above and use the bumpmap to perturb it
         // on to the screen
         Blend one one
         ZWrite off
        Pass {
            Name "BASE"
            Tags { "LightMode" = "Always" }
            
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#pragma fragmentoption ARB_precision_hint_fastest
#include "UnityCG.cginc"

struct appdata_t {
    float4 vertex : POSITION;
    float2 texcoord: TEXCOORD0;
};

struct v2f {    
    float4 vertex : POSITION;    
    float2 uvmain : TEXCOORD0;    
};

float _SparkDist;
float4 _Noise_ST;
float4 _MainTex_ST;
float4 _ObjectScale;

v2f vert (appdata_t v)
{
    v2f o;
    o.vertex = mul(UNITY_MATRIX_MVP, v.vertex);
    
    o.uvmain = TRANSFORM_TEX( v.texcoord, _MainTex );
    return o;
}

sampler2D _GrabTexture;
float4 _GrabTexture_TexelSize;
sampler2D _Noise;
sampler2D _MainTex;
float _GlowSpread;
float _GlowIntensity;
float _StartSeed;
float _SparkMag;
float _SparkWidth;

half4 frag( v2f i ) : COLOR
{
    
    
    float2 noiseVec = float2(i.uvmain.y / 5,abs(sin(_Time.x + _StartSeed)) * 256);    
    float4 noiseSamp = tex2D( _Noise,noiseVec);
        
    float dvdr = 1.0 - abs(i.uvmain.y - 0.5) * 2;
    dvdr = clamp(dvdr+_SparkDist,0,1);
    
    float fullWidth = 1 - _SparkWidth * 2;
    // Center the scaled texture
    float scaledTexel = (i.uvmain.x - _SparkWidth) / fullWidth;
            
    float offs = scaledTexel + ((0.5 - noiseSamp.x)/2) * _SparkMag * dvdr;
    offs = clamp(offs,0,1);
            
    
    float2 texSampVec = float2(offs,i.uvmain.y);
    half4 col = tex2D( _MainTex, texSampVec);

    
    return col;
}
ENDCG
        }
    }


    // ------------------------------------------------------------------
    // Fallback for older cards     
    SubShader {
        Blend one one
         ZWrite off
        Pass {
            Name "BASE"
            SetTexture [_MainTex] {    combine texture }
        }
    }
}

}

用法：

创建个摄像机，挂上上面的脚本，然后把Blur Shader用这个shader赋值就行了