Alpha textures on model?

[Princess Luna]

file-native opacity settings are rarely supported by 3d modeling programs, so an opacity map is needed. an easy way is to set the texture's brightness to 100% and saturation to 0% (to get a completely white semi-transparent texture) and place it over a black layer. thus, an opacity map is made!

they are actual textures, they just have an alpha channel that isnt supported, making it opaque.

Ah I see, now for this opacity map. Can this technique be achieved in Blender as well or is it just 3DsMax?