Unity SplitOutIn Shader

Shader "Custom/SplitOutIn" {
	Properties {
		_MainTex( "2D Texture", 2D ) = "white" {}
		_AlphaMap ("AlphaMap", 2D) = "white" {}
		_AlphaBase( "AlphaBase", Range(-1, 1) ) = 1
	}
	SubShader {
		Tags { 
			"Queue" = "Transparent"
			"RenderType"="Opaque"
		}
		Cull off

		CGPROGRAM
		#pragma surface surf Lambert alpha

		struct Input {
			float2 uv_MainTex;
			float2 uv_AlphaMap;
		};

		sampler2D _MainTex;
		sampler2D _AlphaMap;
		float _AlphaBase;

		void surf (Input IN, inout SurfaceOutput o) {
			o.Alpha = tex2D(_AlphaMap, IN.uv_AlphaMap).rgb - _AlphaBase;
			o.Albedo = tex2D(_MainTex, IN.uv_MainTex).rgb;
		}
		ENDCG
	}
	FallBack "Diffuse"
}