How to assign constant color to albedo in shader?

Questions & Answers
1

Why does the following code render objects as white instead of red?

Shader "Example/Test" {
  Properties {
	_MainTex ("Texture", 2D) = "white" {}
  }
  SubShader {
	Tags { "RenderType" = "Opaque" }
	CGPROGRAM
	#pragma surface surf Lambert
	struct Input {
		float2 uv_MainTex;
	};
	sampler2D _MainTex;
	void surf (Input IN, inout SurfaceOutput o) {
		o.Albedo = (1,0,0,1);
	}
	ENDCG
  }
  Fallback "Diffuse"
}
2

You are using “(1,0,0,1)” instead of “float4(1,0,0,1)”

This should work :

 Shader "Example/Test" {
   Properties {
     _MainTex ("Texture", 2D) = "white" {}
   }
   SubShader {
     Tags { "RenderType" = "Opaque" }
     CGPROGRAM
     #pragma surface surf Lambert
     struct Input {
         float2 uv_MainTex;
     };
     sampler2D _MainTex;
     void surf (Input IN, inout SurfaceOutput o) {
         o.Albedo = float4(1,0,0,1);
     }
     ENDCG
   }
   Fallback "Diffuse"
 }