Rendering Problem
 

When I use Fg with Mental Ray, (oh, and, by the way, I figured out that the way to render the really cool sharp images was by using FG and an incandescent object in the scene) I get a very strange light source that is obviously coming from UNDER an object, but only if the object is touching the ground/plane used as the ground. Odd. Heres a picture of what I mean. I have no other light, except two planes positioned above the cube casting a bluish tinted color. PS this only happenes when a cubic-based model is used. Take a look.

Not sure, but FG uses surface color information to illuminate the scene therefore if your cube is white its logical that it affects the plane color on wich is standing...I gess