there was a doom 3 descent mod which was fairly awesome, but work on it seems to have stopped.
http://www.chmodoplusr.com/IntoCerberon/making it multiplayer would probibly work the best, since theres currently no scriptable access to ai. technically speaking we dont have any real way to override physics either. most of my physics mods (which i keep in a whole other folder), rely on a series of dirty hacks to work. there is no override and no physics hook. but as far as ai is concerned we have almost zero access to it from scripting.
for graphics, its one of those things that would work better if we had more than one uv mapping channel. then you could bake your light maps independant of the diffuse texture(s). this would allow for more texture re-usage in the level and better overall quality for less performance cost.
room based game engines use portholes to separate areas which need not be rendered. say youre in one room and the next room, separated by a door is not rendered until the trigger to open the door is fired. when the door closes the rendering of the adjacent room is shut off. another trick is to include cornered hallways so its impossible to see 2 rooms at the same time. theres usually a couple invisible triggers on each entrance to that angled corridore so that when you pass the first you turn on rendering for the next room and you pass the second turn off rendering to theprevious room. that this is why fps games get away with such high detail.
in freespace we dont have portholes but we do have detail boxes and loding. so if we make each room a ship. we set the first lod distance to only render the entire room if youre within that rooms radius, if you exit the room then the detail either cuts off fast, to an lod with one dummy invisible polygon. if the room is visible from the next then we can lod it down more slowly. the idea is to make it so you can only see a few rooms (ships) at a time.
we may need a few source tweaks though, for example, we need a way to make an object derivative, such as a ship, static. it never moves and never changes its position or orientation. everything tagged as static is transformed to world space once at mission load (instead of every frame which makes it faster). this would be useful for lots of things, terrain, planet models, ect. aligning rooms in fred would be hard enough without them moving about at runtime. some fred tweaks may come in handy to make rooms snap together at certain points or to make the orientation match (especially if rooms are placed at odd angles). might need a few new types of animation trigger that goes off if a player comes near it/touches it/activates it/destroys it, whatever. i dont see that being really hard to do, might even be fairly easy to script. and finally better control of dynamic lighting, such as light emitting textures or glowpoints. most hardware supports around 8 hardware lights. so if each room only has 8 dynamic light sources to deal with then it should work fine. room lights should be able to be activated by lod or distance. so that only lights in the current room are rendered as well as lights from weapons or player ships.
do that and a descent mod for freespace is possible. but i think it would be a lot of work to do right. frankly the idea of a descent mod is daunting. while i realy wouldnt want to do any level design or modeling in general id be happy to provide such a mod team with at least some script support (i have some mercury missile effects already working in game and have managed to get guided missiles to work as well as other descent like weapons) and perhaps il finish my pyro ix model for it.
