实验目的：在Deferred渲染路径下ForwardBass是否会被执行？

Shader "Custom/noDeferredSurf_1" {
	Properties {
		_MainTex ("Base (RGB)", 2D) = "white" {}
	}
	SubShader {
		Tags { "RenderType"="Opaque" }
		LOD 200
		//.1
		Pass {
			Tags {"LightMode"="ForwardBase"}
			CGPROGRAM
			#pragma vertex vert
			#pragma fragment frag
			#include "UnityCG.cginc"
			#include "Lighting.cginc"
			struct vertOut {
				float4 pos:SV_POSITION;
				float4 color:COLOR;
			};
			vertOut vert(appdata_base v)
			{
				vertOut o;
				o.pos = mul(UNITY_MATRIX_MVP, v.vertex);
				o.color = float4(0, 1, 0, 1);//输出绿色
				return o;
			}
			float4 frag(vertOut i):COLOR
			{
				return i.color;
			}
			ENDCG
		}
		//.2
		Blend One One
		CGPROGRAM
		//exclude_path:prepass参数告诉Unity不要为Deferred渲染路径产生Shader
		#pragma surface surf Lambert exclude_path:prepass
		#pragma debug
		sampler2D _MainTex;

		struct Input {
			float2 uv_MainTex;
		};

		void surf (Input IN, inout SurfaceOutput o) {
			half4 c = tex2D (_MainTex, IN.uv_MainTex);
			o.Albedo = c.rgb;
			o.Alpha = c.a;
		}
		ENDCG
	} 
	FallBack Off
}

效果

结论：

在Deferred渲染路径下，没有适合于Deferred模式的Pass，Unity会执行适合于Forward模式的Pass