@One Eyed Jack: I'm certainly not the right person, as I didn't do any serious 3d development since quite a time.
@halo: this is certainly a good solution and I have no doubt you have made a lot of tests and research on the subject, but but isn't Doom3 precisely using portals?
And actually, polygons aren't really necessarily the future of the "use established general purpose modelers and not custom made ones" way. Because it's been a while that modelers work with subdivision surfaces, and with the increasing power and the use of vertex shaders, complete subdivision surface implementations may very well be efficiently done in real time pretty soon. And subdisvision surfaces save a lot of memory. But that's just a wild (but advised I think) guess.
@halo: this is certainly a good solution and I have no doubt you have made a lot of tests and research on the subject, but but isn't Doom3 precisely using portals?
And actually, polygons aren't really necessarily the future of the "use established general purpose modelers and not custom made ones" way. Because it's been a while that modelers work with subdivision surfaces, and with the increasing power and the use of vertex shaders, complete subdivision surface implementations may very well be efficiently done in real time pretty soon. And subdisvision surfaces save a lot of memory. But that's just a wild (but advised I think) guess.