unity shader—高斯模糊效果

正常图：

高斯模糊效果图：

shader代码：

Shader "Custom/GaoSiMoHu"
{
	Properties
	{
		_MainTex ("Texture", 2D) = "white" {}
		_BlurSize("Blur size",Float)=1.0
	}
	SubShader
	{
		ZTest Always
		cull off
		ZWrite off

		CGINCLUDE//这个可以使其他pass块都可以使用，而不用在两个pass里都写，减少了写的次数
		sampler2D _MainTex;
		half4 _MainTex_TexelSize;
		float _BlurSize;
		struct v2f{
			float4 pos:SV_POSITION;
			half2 uv[5]:TEXCOORD0;
		};
		fixed4 fragBlur(v2f i):SV_Target{
			float weight[3]={
				0.4026,
				0.2442,
				0.0545
			};

			fixed3 sum = tex2D(_MainTex,i.uv[0]).rgb * weight[0];

			for(int it = 1; it < 3; it++){
				sum += tex2D(_MainTex,i.uv[it]).rgb * weight[it];
				sum += tex2D(_MainTex,i.uv[2 * it]).rgb * weight[it];
			}

			return fixed4(sum,1.0);
		}
		ENDCG

		Pass{
			NAME "GAUSSIAN_BLUR_VERTICAL"//这个pass的唯一名字，可以在其他地方调用，usepass + 名字
			CGPROGRAM

			#pragma vertex vertlurVertical
			#pragma fragment fragBlur
			#include "UnityCG.cginc"
			
			v2f vertlurVertical(appdata_img v){
				v2f o;
				o.pos = UnityObjectToClipPos(v.vertex);
				half2 uv = v.texcoord;
				o.uv[0]=uv;
				o.uv[1]=uv + float2(0.0,_MainTex_TexelSize.y * 1.0) * _BlurSize;
				o.uv[2]=uv - float2(0.0,_MainTex_TexelSize.y * 1.0) * _BlurSize;
				o.uv[3]=uv + float2(0.0,_MainTex_TexelSize.y * 2.0) * _BlurSize;
				o.uv[4]=uv - float2(0.0,_MainTex_TexelSize.y * 2.0) * _BlurSize;

				return o;
			}
			ENDCG
		}

		Pass{
			NAME "GAUSSIAN_BLUR_HORIZONTAL"
			CGPROGRAM
			#pragma vertex vertlurHorizontal
			#pragma fragment fragBlur
			#include "UnityCG.cginc"

			v2f vertlurHorizontal(appdata_img v){
				v2f o;
				o.pos = UnityObjectToClipPos(v.vertex);
				half2 uv = v.texcoord;
				o.uv[0]=uv;
				o.uv[1]=uv + float2(0.0,_MainTex_TexelSize.x * 1.0) * _BlurSize;
				o.uv[2]=uv - float2(0.0,_MainTex_TexelSize.x * 1.0) * _BlurSize;
				o.uv[3]=uv + float2(0.0,_MainTex_TexelSize.x * 2.0) * _BlurSize;
				o.uv[4]=uv - float2(0.0,_MainTex_TexelSize.x * 2.0) * _BlurSize;

				return o;
			}
			ENDCG
		}
	}
}

调节_BlurSize即可看到效果