Unity支持置灰的Alpha Blend Shader

支持置灰的Alpha Blend Shader

Shader "SnoopyShader/Alpha Blend"
{
	Properties
	{
		_MainTex("Main Texture", 2D) = "white" {}
		//置灰开关
		[Toggle(OpenGray)] _OpenGray("OpenGray", Int) = 0
	}

	SubShader
	{
		Tags
		{
			"RenderType" = "Transparent"
			"Queue" = "Transparent"
			"IgnoreProjector" = "True"
		}

		Pass
		{
			Tags{"LightMode" = "ForwardBase"}
		ZWrite Off
		Blend SrcAlpha OneMinusSrcAlpha

		CGPROGRAM
		#pragma vertex vert
		#pragma fragment frag
		#pragma target 3.0
		#pragma shader_feature OpenGray
		#include "UnityCG.cginc"

		sampler2D _MainTex;
		fixed4 _MainTex_ST;

		struct appdata
		{
			float4 vertex : POSITION;
			fixed4 color : COLOR;
			float2 uv : TEXCOORD0;
		};

		struct v2f
		{
			float4 pos : SV_POSITION;
			fixed4 color : COLOR;
			float2 uv : TEXCOORD0;
		};

		v2f vert(appdata v)
		{
			v2f o;
			o.pos = UnityObjectToClipPos(v.vertex);
			o.color = v.color;
			o.uv = TRANSFORM_TEX(v.uv, _MainTex);
			return o;
		}

		fixed4 frag(v2f i) : SV_TARGET
		{
			fixed4 albedo = tex2D(_MainTex, i.uv) * i.color;
			//置灰颜色
#if OpenGray
			float grey = dot(albedo.rgb, float3(0.299, 0.587, 0.114));
			albedo.rgb = float3(grey, grey, grey);
#endif
			return albedo;
		}

		ENDCG
	}
	}

		Fallback "Diffuse"
}

设置置灰代码,材质球用上面的shader，然后材质球用设置关键字来出来

material.EnableKeyword("OpenGray");