Alpha Punch Through
From NWN1 Custom Content Guide
[edit] What is it?
NWN's graphical engine, unfortunately, only supports one layer of alpha transparency for textures. If you have multiple objects with a texture with an alpha channel, the closest objects to the camera will display, but the ones behind it will suffer a cookie cutter effect to the fog or the next object that does not use a transparent texture.
For example, see this pine tree:
You will notice the edges around the leaves punching through to the ground (since the snow texture has no alpha).
[edit] Fixing
Well, the easiest tip would be to not overlay objects with an alpha transparency, but that's difficult if you're dealing with objects like the leaves of a tree.
