The Doom 3 engine was impressive and it still is even now, just isn't a versatile engine, as mentioned mostly suited to corridor crawlers. Untweaked, the Doom 3 engine does not perform well in very brightly lit environments. I read it somewhere in The Making of Doom 3 book, just the way the game is coded.
Can't say anything about id's next gen engine at this point. Those little images certainly don't reveal much.
Can't say anything about id's next gen engine at this point. Those little images certainly don't reveal much.