shader实现毛玻璃效果解析，毛玻璃是很多项目需要的效果，以下是毛玻璃的效果代码：

Shader "Custom/WaterBlur" {  
    Properties {  
    _blurSizeXY("BlurSizeXY", Range(0,15)) = 2  
}  
    SubShader {  
        Tags {
            "IgnoreProjector"="True"
            "Queue"="Transparent"
            "RenderType"="Transparent"
            "CanUseSpriteAtlas"="True"
            "PreviewType"="Plane"
        }
        //获取屏幕纹理，必须的
        GrabPass { }  
        // Render the object with the texture generated above  
        Pass {  
             CGPROGRAM  
            #pragma debug  
            #pragma vertex vert  
            #pragma fragment frag   
            #pragma target 3.0  
            //屏幕纹理定义
            sampler2D _GrabTexture : register(s0);  
            float _blurSizeXY;  

            struct data {  
            float4 vertex : POSITION;  
            float3 normal : NORMAL;  
            };  
            struct v2f {  
            float4 position : POSITION;  
            float4 screenPos : TEXCOORD0;  
            };  
           v2f vert(data i){  
           v2f o;  
           o.position = UnityObjectToClipPos(i.vertex);  
           o.screenPos = o.position;  
           return o;  
           }  
           //核心逻辑就是使用多次采样纹理，然后混合多次，采样的对象是屏幕纹理，实现高斯模糊
           half4 frag( v2f i ) : COLOR  
           {  
           //模糊的原理就是错开uv来采样，实现模糊
           float2 screenPos = i.screenPos.xy / i.screenPos.w;  
           float depth= _blurSizeXY*0.0005;  
           screenPos.x = (screenPos.x + 1) * 0.5;  

           screenPos.y = 1-(screenPos.y + 1) * 0.5;  

           half4 sum = half4(0.0h,0.0h,0.0h,0.0h);     
           sum += tex2D( _GrabTexture, float2(screenPos.x-5.0 * depth, screenPos.y+3.0 * depth)) * 0.025;      
           sum += tex2D( _GrabTexture, float2(screenPos.x+5.0 * depth, screenPos.y-3.0 * depth)) * 0.025;  

           sum += tex2D( _GrabTexture, float2(screenPos.x-4.0 * depth, screenPos.y+2.5 * depth)) * 0.05;  
           sum += tex2D( _GrabTexture, float2(screenPos.x+4.0 * depth, screenPos.y-2.5 * depth)) * 0.05;  


           sum += tex2D( _GrabTexture, float2(screenPos.x-3.0 * depth, screenPos.y+2.0 * depth)) * 0.09;  
           sum += tex2D( _GrabTexture, float2(screenPos.x+3.0 * depth, screenPos.y-2.0 * depth)) * 0.09;  

           sum += tex2D( _GrabTexture, float2(screenPos.x-2.0 * depth, screenPos.y+1.5 * depth)) * 0.12;  
           sum += tex2D( _GrabTexture, float2(screenPos.x+2.0 * depth, screenPos.y-1.5 * depth)) * 0.12;  

           sum += tex2D( _GrabTexture, float2(screenPos.x-1.0 * depth, screenPos.y+1.0 * depth)) *  0.15;  
           sum += tex2D( _GrabTexture, float2(screenPos.x+1.0 * depth, screenPos.y-1.0 * depth)) *  0.15;  

           sum += tex2D( _GrabTexture, screenPos-3.0 * depth) * 0.025;      
           sum += tex2D( _GrabTexture, screenPos-2.5 * depth) * 0.05;  
           sum += tex2D( _GrabTexture, screenPos-2.0 * depth) * 0.09;  
           sum += tex2D( _GrabTexture, screenPos-1.5 * depth) * 0.12;  
           sum += tex2D( _GrabTexture, screenPos-1.0 * depth) * 0.15;      
           sum += tex2D( _GrabTexture, screenPos) * 0.16;   
           sum += tex2D( _GrabTexture, screenPos+3.0 * depth) * 0.15;  
           sum += tex2D( _GrabTexture, screenPos+2.5 * depth) * 0.12;  
           sum += tex2D( _GrabTexture, screenPos+2.0 * depth) * 0.09;  
           sum += tex2D( _GrabTexture, screenPos+1.5 * depth) * 0.05;  
           sum += tex2D( _GrabTexture, screenPos+1.0 * depth) * 0.025;           
           return sum/2;  
           }  
           ENDCG  
        }  
    }  
   Fallback Off  
}  

这是实现效果：

我们可以用Dotween插件来控制模糊的程度，可以实现很好的效果，有如下代码：

/// 主页按钮点击回调
    /// 
    private void HimebtnHundler()
    {
        _leftpic.transform.DOLocalMoveX(-746f, 1);
        _rightpic.transform.DOLocalMoveX(787f, 1);
        _material.DOFloat(0, "_blurSizeXY", 1);
        _word.GetComponent().DOFade(0, 1f);
        StartCoroutine(CloseErrorView());
    }

这段代码，主要是增加CanvasGroup组件，实现对整个场景的alpha控制：

主要用DOFade来实现CanvasGroup，用DOFloat对材质球上的shader属性的控制!