fragment Shader 内で Surface shader を展開する例

fragWithSurfSample.shader

#include "UnityPBSLighting.cginc"

fixed4 frag(v2f i) : SV_Target
{
	Input surfIN;
	UNITY_INITIALIZE_OUTPUT(Input, surfIN);
	SurfaceOutputStandard o;
	UNITY_INITIALIZE_OUTPUT(SurfaceOutputStandard, o);
	surf(surfIN, o);
	return fixed4(o.Albedo,0);
}

void surf(Input IN, inout SurfaceOutputStandard o)
{
   fixed4 c = tex2D(_MainTex, IN.uv_MainTex) * _Color;
   o.Albedo = c.rgb;
   o.Metallic = _Metallic;
   o.Smoothness = _Glossiness;
   o.Alpha = c.a;
}