Nice technique Ace. Never even thought about that yet. Sounds like it has alot of potential for my application. I've almost got a nice volumetric layer done as well but I'm concerned about the frame rate with those huge models required to do a nice layering effect. My intent was to scale the alpha level of the different "fog" layers based on the current weather state. I could run it at 0 alpha for sunny days and then fog it in to about 50 or 60 alpha for rain and overcast. Obviously this isn't what I'd call a show stopper in my game development, and the weather thing is really just an eye-candy by product of cleaning up the clipping code for a professional looking horizon. Between that scene effect and a customized 3-4 layer model above the player's head I should have the effect I am looking for. Might not be perfect but should be getting close =)

Thanks for the suggestion.

Mark