Unity Shader 屏幕后处理反相

Shader代码如下：

	Properties
	{
		_MainTex ("Base (RGB)", 2D) = "white" {}//渲染纹理
	}
	SubShader {
		Pass {  
			ZTest Always Cull Off ZWrite Off
			
			CGPROGRAM
			
			#include "UnityCG.cginc"
			
			#pragma vertex vert  
			#pragma fragment frag
			
			sampler2D _MainTex;  


			
			struct v2f 
			{
				float4 pos : SV_POSITION;
				float2 uv:TEXCOORD0;
			};
			  
			v2f vert(appdata_img v) {
				v2f o;
				o.pos = UnityObjectToClipPos(v.vertex);
				o.uv = v.texcoord;
				return o;
			}
			
			
			fixed4 frag(v2f i) : SV_Target {
				return fixed4(fixed3(1.0 - tex2D(_MainTex,i.uv).rgb),1.0);
 			}
			
			ENDCG
		} 
	}
	FallBack Off
}

效果如下：