Alpha Huds For Mesh Avatars

[Fei Fang]

Hey, I'm a 3d character artist who recently decided to make some avatars to sell on Second Life. I'm just having a difficult time understanding things like how an alpha hud works. I've begun to research how to make huds and basic scripting, but I can't find much information on what I'm looking for.

 

I want to make avatars with customizable options like an alpha hud so people won't cry and throw stuff at me because they can't wear clothes. Is anyone able to point me in the right direction? I thought maybe it was just swapping different textures, but I'm not sure that's the case. Most huds I've seen can hide multiple parts at once, so there seems to be many combinations.