Will doom3 use Unreal2 Math Engine?

Or whatever they call it. I mean that if you shoot someone the monster och human falls down and dies realistic or from a high place like a house and it falls down and hits a rock and it won't go through the rock ( or the body hangs in the air ) instedd it lays on the rock realistic.

You're talking about the Physics engine. Unreal 2 uses technology licensed from someone else, so in theory id could use the same technology for Doom.

But as far as anyone knows, they're developing their own physics engine. We're yet to see any good examples of it, though.

It has been described how your "space janitor" got wiggled around with by the pinky in the bathroom scene. We haven't seen it ourselves, but ain't that a good example anyway?

i'd like to see this physics engine can do more than "looking cool" stuff.something like,if the imp is shot (not deat yet).it should not only fall back realistcally ,but it also can be shot off the ledge and can be dead by fall damage.