解决灰色shader与mask冲突的方案

Shader "Custom/Opaque"
{
Properties
{
[PerRendererData] _MainTex ("Sprite Texture", 2D) = "white" {}
_Color ("Tint", Color) = (1,1,1,1)

// required for UI.Mask
_StencilComp ("Stencil Comparison", Float) = 8
_Stencil ("Stencil ID", Float) = 0
_StencilOp ("Stencil Operation", Float) = 0
_StencilWriteMask ("Stencil Write Mask", Float) = 255
_StencilReadMask ("Stencil Read Mask", Float) = 255
_ColorMask ("Color Mask", Float) = 15
}
SubShader
{
Tags
{
// ...
}

// required for UI.Mask
Stencil
{
Ref [_Stencil]
Comp [_StencilComp]
Pass [_StencilOp]
ReadMask [_StencilReadMask]
WriteMask [_StencilWriteMask]
}
ColorMask [_ColorMask]

Pass
{
// ...
}
}
}

Shader "UI/Default Gray"
{
Properties
{
[PerRendererData] _MainTex("Sprite Texture", 2D) = "white" {}
_Color("Tint", Color) = (1,1,1,1)
_MyColor("MyColor", Color) = (1,1,1,1)

// required for UI.Mask
_StencilComp("Stencil Comparison", Float) = 8
_Stencil("Stencil ID", Float) = 0
_StencilOp("Stencil Operation", Float) = 0
_StencilWriteMask("Stencil Write Mask", Float) = 255
_StencilReadMask("Stencil Read Mask", Float) = 255
_ColorMask("Color Mask", Float) = 15
}

SubShader
{
Tags
{
"Queue" = "Transparent"
"IgnoreProjector" = "True"
"RenderType" = "Transparent"
"PreviewType" = "Plane"
"CanUseSpriteAtlas" = "True"
}
// 源rgba*源a + 背景rgba*(1-源A值)
Blend SrcAlpha OneMinusSrcAlpha

Cull Off ZWrite Off ZTest Always

Pass
{

Stencil
{
Ref[_Stencil]
Comp[_StencilComp]
Pass[_StencilOp]
ReadMask[_StencilReadMask]
WriteMask[_StencilWriteMask]
}
ColorMask[_ColorMask]

CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"

struct appdata_t
{
float4 vertex   : POSITION;
float4 color    : COLOR;
float2 texcoord : TEXCOORD0;
};

struct v2f
{
float4 vertex   : SV_POSITION;
fixed4 color : COLOR;
half2 texcoord  : TEXCOORD0;
};

sampler2D _MainTex;
fixed4 _Color;
fixed4 _MyColor;

v2f vert(appdata_t IN)
{
v2f OUT;
OUT.vertex = mul(UNITY_MATRIX_MVP, IN.vertex);
OUT.texcoord = IN.texcoord;
#ifdef UNITY_HALF_TEXEL_OFFSET
OUT.vertex.xy -= (_ScreenParams.zw - 1.0);
#endif
OUT.color = IN.color * _Color;
return OUT;
}

fixed4 frag(v2f IN) : SV_Target
{
half4 color = tex2D(_MainTex, IN.texcoord) * IN.color;
float grey = dot(color.rgb, fixed3(0.22, 0.707, 0.071));
return half4(grey*_MyColor.r,grey*_MyColor.g,grey*_MyColor.b,color.a);
}
ENDCG
}
}
}