项目中经常使用高斯模糊效果，主要原理是，生成8张图片分别想8各方偏移。

Shader "hongGe/GrabTexture3"{    Properties    {        _Offset ("UVOffset", float) = 0.01//uv偏移        _Percent ("Percent", float) = 0.1//百分比    }    SubShader    {        Tags{"Queue"="Transparent"}        GrabPass{}             Pass        {            CGPROGRAM            #pragma vertex vert            #pragma fragment frag            #include "UnityCG.cginc"            sampler2D _GrabTexture;            float _Offset;            float _Percent;                         struct VertexOutput            {                float4 pos:SV_POSITION;                float2 uv:TEXCOORD0;            };                         VertexOutput vert(appdata_base v)            {                VertexOutput o;                o.pos = mul(UNITY_MATRIX_MVP,v.vertex);                o.uv = float2(v.texcoord.x , 1-v.texcoord.y);                                 return o;            }                         float4 frag(VertexOutput input):COLOR            {                half4 a = tex2D(_GrabTexture,input.uv + float2(_Offset,0));                half4 b = tex2D(_GrabTexture,input.uv + float2(-_Offset,0));                half4 c = tex2D(_GrabTexture,input.uv + float2(0,_Offset));                half4 d = tex2D(_GrabTexture,input.uv + float2(0,-_Offset));                                 half4 e = tex2D(_GrabTexture,input.uv + float2(_Offset / 2,_Offset / 2));                half4 f = tex2D(_GrabTexture,input.uv + float2(-_Offset / 2,_Offset / 2));                half4 g = tex2D(_GrabTexture,input.uv + float2(_Offset / 2,-_Offset / 2));                half4 h = tex2D(_GrabTexture,input.uv + float2(-_Offset / 2,-_Offset / 2));                                 half4 texCol = tex2D(_GrabTexture,input.uv);                texCol = (texCol + a + b + c + d + e + f + g + h) * _Percent;                return texCol;            }            ENDCG        }    }    FallBack "Diffuse"}