Unity渲染在所有层之上的shader

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


_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" = "Overlay"
"IgnoreProjector" = "True"
"RenderType" = "Transparent"
"PreviewType" = "Plane"
"CanUseSpriteAtlas" = "True"
}


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


Cull Off
Lighting Off
ZWrite Off
ZTest Off
Blend SrcAlpha OneMinusSrcAlpha
ColorMask[_ColorMask]


Pass
{
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;
};


fixed4 _Color;


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)*float2(-1,1);
#endif
OUT.color = IN.color * _Color;
return OUT;
}


sampler2D _MainTex;


fixed4 frag(v2f IN) : SV_Target
{
half4 color = tex2D(_MainTex, IN.texcoord) * IN.color;
clip(color.a - 0.01);
return color;
}
ENDCG
}
}
}