What is the alpha channel supposed to be in a packed texture?
I know it's usually
>Green=Roughness
>Blue=Specular
But what's the alpha? The metallic? What's weird is that this is in a Normal Map, not even the Albedo. The Albedo ALSO has a separate packed alpha.
Is there an industry standard?
It looks like a Metallic map to me, but I don't know?