Alpha mesh

An alpha mesh is a mesh that has two (or more) layers. Usually, the outer layer can be totally blanked out (made transparent) or can be made with any degree of transparency.

For example, Marvine's Alpha Mesh, available in [1], when opened by Bodyshop, generate two sets of bitmaps:

• an outer layer (the skirt)
• an inner layer (the body)

It's possible to totally blank out the alpha file in the outer layer (which would show the body as if painted by the inner layer), or it's possible to make it totally opaque (and the sims would be using a normal looking dress) or - most interesting - it's possible to paint the outer layer with shades of grey, and then the skirt would look diaphanous.