by Kessler » Sun May 30, 2010 11:18 am
The only difference I am aware of is the portal sky function in RoE (a skybox that is practically a camera view of another room, with models and stuff in it to create a panorama). Portal sky also works in regular Doom3 with the help of a mod.
But it is the same engine, RoE just has new media added and some extra functionality unlocked.