Unity - 着色器中的 AlphaToMask 似乎不适用于移动设备(透明度)

Question

我在网上找到了这个着色器，它模仿了容器中的液体运动。

这里是(https://pastebin.com/wRWnHQH2(

Shader "Unlit/SpecialFX/Liquid"
{
Properties
{
_Tint ("Tint", Color) = (1,1,1,1)
_MainTex ("Texture", 2D) = "white" {}
_FillAmount ("Fill Amount", Range(-10,10)) = 0.0
[HideInInspector] _WobbleX ("WobbleX", Range(-1,1)) = 0.0
[HideInInspector] _WobbleZ ("WobbleZ", Range(-1,1)) = 0.0
_TopColor ("Top Color", Color) = (1,1,1,1)
_FoamColor ("Foam Line Color", Color) = (1,1,1,1)
_Rim ("Foam Line Width", Range(0,0.1)) = 0.0    
_RimColor ("Rim Color", Color) = (1,1,1,1)
_RimPower ("Rim Power", Range(0,10)) = 0.0
}
SubShader
{
Tags {"Queue"="Geometry"  "DisableBatching" = "True" }
Pass
{
Zwrite On
Cull Off // we want the front and back faces
AlphaToMask On // transparency
CGPROGRAM

#pragma vertex vert
#pragma fragment frag
// make fog work
#pragma multi_compile_fog
#include "UnityCG.cginc"
struct appdata
{
float4 vertex : POSITION;
float2 uv : TEXCOORD0;
float3 normal : NORMAL; 
};
struct v2f
{
float2 uv : TEXCOORD0;
UNITY_FOG_COORDS(1)
float4 vertex : SV_POSITION;
float3 viewDir : COLOR;
float3 normal : COLOR2;    
float fillEdge : TEXCOORD2;
};
sampler2D _MainTex;
float4 _MainTex_ST;
float _FillAmount, _WobbleX, _WobbleZ;
float4 _TopColor, _RimColor, _FoamColor, _Tint;
float _Rim, _RimPower;
float4 RotateAroundYInDegrees (float4 vertex, float degrees)
{
float alpha = degrees * UNITY_PI / 180;
float sina, cosa;
sincos(alpha, sina, cosa);
float2x2 m = float2x2(cosa, sina, -sina, cosa);
return float4(vertex.yz , mul(m, vertex.xz)).xzyw ;            
}

v2f vert (appdata v)
{
v2f o;
o.vertex = UnityObjectToClipPos(v.vertex);
o.uv = TRANSFORM_TEX(v.uv, _MainTex);
UNITY_TRANSFER_FOG(o,o.vertex);        
// get world position of the vertex
float3 worldPos = mul (unity_ObjectToWorld, v.vertex.xyz);  
// rotate it around XY
float3 worldPosX= RotateAroundYInDegrees(float4(worldPos,0),360);
// rotate around XZ
float3 worldPosZ = float3 (worldPosX.y, worldPosX.z, worldPosX.x);     
// combine rotations with worldPos, based on sine wave from script
float3 worldPosAdjusted = worldPos + (worldPosX  * _WobbleX)+ (worldPosZ* _WobbleZ);
// how high up the liquid is
o.fillEdge =  worldPosAdjusted.y + _FillAmount;
o.viewDir = normalize(ObjSpaceViewDir(v.vertex));
o.normal = v.normal;
return o;
}
fixed4 frag (v2f i, fixed facing : VFACE) : SV_Target
{
// sample the texture
fixed4 col = tex2D(_MainTex, i.uv) * _Tint;
// apply fog
UNITY_APPLY_FOG(i.fogCoord, col);
// rim light
float dotProduct = 1 - pow(dot(i.normal, i.viewDir), _RimPower);
float4 RimResult = smoothstep(0.5, 1.0, dotProduct);
RimResult *= _RimColor;
// foam edge
float4 foam = ( step(i.fillEdge, 0.5) - step(i.fillEdge, (0.5 - _Rim)))  ;
float4 foamColored = foam * (_FoamColor * 0.9);
// rest of the liquid
float4 result = step(i.fillEdge, 0.5) - foam;
float4 resultColored = result * col;
// both together, with the texture
float4 finalResult = resultColored + foamColored;               
finalResult.rgb += RimResult;
// color of backfaces/ top
float4 topColor = _TopColor * (foam + result);
//VFACE returns positive for front facing, negative for backfacing
return facing > 0 ? finalResult: topColor;
}
ENDCG
}
}
}

它运行良好，除了在桌面上工作以遮盖填充部分的 AlphaToMask ON 似乎在移动设备上根本不起作用，显示黑色而不是透明度。

关于发生了什么或我如何解决这个问题的任何线索？

Answer 1

对于那些希望它在移动设备上运行的人，只需将AlphaToMask设置为关闭(可选(，将Zwrite设置为关闭并在Zwrite off行下方添加行Blend SrcAlpha OneMinusSrcAlpha， 还设置"Queue"="Transparent"或"AlphaTest"

SubShader
{
Tags {"Queue"="Transparent"  "DisableBatching" = "True" }
Pass
{
Zwrite off
Blend SrcAlpha OneMinusSrcAlpha
Cull Off // we want the front and back faces
AlphaToMask off CGPROGRAM
#pragma vertex vert
#pragma fragment frag

(完整代码( (演示图片(

另请参阅：

Unity Blend Documentation：https：//docs.unity3d.com/Manual/SL-Blend.html

Unity 着色器透明教程：制作透明着色器 [6/8]