From
http://www.gamespy.com/e32002/pc/doom3b
"(Ed. note: in a later interview with Robert Duffy, it was explained that the BSP process is still present, but the lighting and visibility calculations are no longer necessary, as they're handled by the engine in real time.)"
"One of the more interesting technical innovations we saw is a new GUI system that allows for Flash-like animation on any surface, and can be completely interactive. Unlike most current games, where a keypad or switch might be portrayed with a few simple textures, these items can now be presented with much more detail."
"A number of other significant changes have also been made for the new engine. Textures are no longer simply painted -- they're now models with complete bump-mapping. Models are so detailed that you can see pores on a character's face or even the individual hairs on their head, and a skeletal animation system allowing for blending of multiple animations should make character movements appear more natural."
"On the other side of the fence, we uncovered a major bit of info that will be of particular interest to mod developers: the development tools are built into the game's executable. So, as Stratton put it "when you're running the game, you're running the editor." What this means is that you'll be able to walk around in a level, press a key, bring up the editor, place some lights, and go back to the level. It seems the old
.BSP process is gone, and will be replaced by something different, so while this may be a bit of a learning curve for mappers, they can rest easy knowing that tools will be included with the game."