Shader "Custom/NewSurfaceShader" {    Properties {        _Color ("Color", Color) = (1,1,1,1)        _MainTex ("Albedo (RGB)", 2D) = "white" {}        _Glossiness ("Smoothness", Range(0,1)) = 0.5        _Metallic ("Metallic", Range(0,1)) = 0.0    }    SubShader {        Tags { "RenderType"="Opaque" }        LOD 200                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(0,0,0);#else            o.Albedo = float3(1,1,1);#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");    }}