Perhaps someone could help me out? I was just curious which maps are needed to be baked for glass or semi transparent materials such as gemstones to render correctly in a game engine? It would need to be pair with an alpha map for Diffuse material to become transparent also?
That will depend if you want your transparency to vary across the surface. If yes, then you will need an alpha map.
If you are fine with a constant transparency, then just bake a diffuse map as if you were making an opaque object and set the transparency to a constant value in the game engine.
At least, that’s how I would do it in Unreal. If you use an other engine, you will have to know how its shading system works.
It’s for Skyrim SE and it uses the NetImmerse Engine. From my experience it can handle transparency in terms of alpha for leaves and foliage but am experimenting in terms of translucent/transparent materials.