Shader with separate alpha texture black rather than transparent

Questions & Answers
1

I’m using a shader that I found here; it works great except the area of the main texture that I need to be transparent is black instead. The blue cloud is the plane that the shader is attached to. It should look like the top illustration, but what I actually see is below it.

33433-separate-alpha-illustration.jpg

I’m new to writing shaders, and I have no idea what may be the problem. Thanks!

Shader "Unlit/TransparentSeperateAlpha"
{
	Properties
	{
		_MainTex ("Base", 2D) = "white" {}
		_AlphaTex("BaseA", 2D) = "white" {}
	}
 
	SubShader
	{
		Tags {"Queue"="Transparent" "IgnoreProjector"="True" "RenderType"="Transparent"}
		LOD 100
		 
		ZWrite Off
		Blend SrcAlpha OneMinusSrcAlpha
		 
		Pass
		{
			Lighting Off
			SetTexture [_MainTex]
			{
				Combine texture
			}
			SetTexture [_AlphaTex]
			{
				Combine texture * previous
			 
			}
		}
	}
}
2

Solved it! It wasn’t the shader but rather the input. My texture that I assigned to _AlphaTex didn’t actually have an alpha channel. No wonder! Hope my mistake helps someone else looking for a similar solution.