Unity3D Shader ：模糊效果

Shader "Unlit/Test"
{
Properties
{
_MainTex ("Texture", 2D) = "white" {}
_Offset("Offset",Range(0.000,0.010))=0.000
}
SubShader
{
Tags { "RenderType"="Opaque" }
LOD 100


Pass
{
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;
};


sampler2D _MainTex;
float4 _MainTex_ST;
float _Offset;

v2f vert (appdata v)
{
v2f o;
o.vertex = UnityObjectToClipPos(v.vertex);
o.uv = TRANSFORM_TEX(v.uv, _MainTex);
return o;
}

fixed4 frag (v2f i) : SV_Target
{
fixed4 col = tex2D(_MainTex, i.uv);
float4 outup;
fixed4 s1 = tex2D(_MainTex, i.uv + float2(_Offset, 0.000));
fixed4 s2 = tex2D(_MainTex, i.uv + float2(-_Offset, 0.000));
fixed4 s3 = tex2D(_MainTex, i.uv + float2(0.000, _Offset));
fixed4 s4 = tex2D(_MainTex, i.uv + float2(0.000, -_Offset));
float pct = 0.2;
outup = col * pct + s1 * pct + s2 * pct + s3 * pct + s4 * pct;
return outup;
}
ENDCG
}
}

}