Originally Posted by gmontem
If the Doom 3 engine can handle outdoors well then why in mars are people still using 2D images for the background?
That's a problem of mappers, not of the engine. Unreal Engine had the capability to use complex 3D enviroments as skyboxes since the beginning, yet many maps (even in UT2004) have a very simple cylindrical or hemispherical background. Dunno about Doom engine, but Quake 3 engine had similar capabilities.