Fog DOES have a use in keeping FPS high. view.fog_start and view.fog_end give huge control over fog. view.fog_end is the point far enough from the camera where nothing is visible. This way you can safely use clip_range without actually seeming like clipping is used. Great for REALLY foggy levels, because then you can increase the detail of the level without worrying about slideshow FPS.

Thanks, MarkMcFear, for all these tips. I will use them, and give them to my team's level builder!

Julian