Shader "Custom/NewSurfaceShader" {

    Properties {

        _Color ("Color", Color) = (,,,)

        _MainTex ("Albedo (RGB)", 2D) = "white" {}

        _Glossiness ("Smoothness", Range(,)) = 0.5

        _Metallic ("Metallic", Range(,)) = 0.0

    }

    SubShader {

        Tags { "RenderType"="Opaque" }

        LOD 

        CGPROGRAM

        // Physically based Standard lighting model, and enable shadows on all light types

        #pragma surface surf Standard fullforwardshadows

        // Use shader model 3.0 target, to get nicer looking lighting

        #pragma target 3.0

        #pragma shader_feature KEYWORD1

        sampler2D _MainTex;

        struct Input {

            float2 uv_MainTex;

        };

        half _Glossiness;

        half _Metallic;

        fixed4 _Color;

        void surf (Input IN, inout SurfaceOutputStandard o) {

            // Albedo comes from a texture tinted by color

            fixed4 c = tex2D (_MainTex, IN.uv_MainTex) * _Color;

#ifdef KEYWORD1

            o.Albedo = float3(,,);

#else

            o.Albedo = float3(,,);

#endif

            // Metallic and smoothness come from slider variables

            o.Metallic = _Metallic;

            o.Smoothness = _Glossiness;

            o.Alpha = c.a;

        }

        ENDCG

    }

    FallBack "Diffuse"

}

using UnityEngine;

using System.Collections;

public class ShaderKeywordTest : MonoBehaviour

{

    public Material mat;

    void OnEnable()

    {

        mat.EnableKeyword("KEYWORD1");

    }

    void OnDisable()

    {

        mat.DisableKeyword("KEYWORD1");

    }

}