How did the SD team make the caves in Fueldump and Oasis? I have tried several times only to deform terrain 
Caves
If i remember right from another post here, they first made em out of brushes and then made a .ase model of it. Could aslo been a md3 model, but i am pretty sure they made a model of it.
This is probably the best way to go, bu tu could also use simple path_meshes and transform them in the 3D-window by vertex editing them.
All I done was place a few simple brushes through my terrain on where I want my caves/tunnels to be (walls, floor and roof).
From there I selected each part of the terrain one by one and rasised into the roof brush (always double checking to see if it deforms the terrain).
Once I finally got that done I then droped in brushes on the roof and went vertex and created a life like cave roof and same for the walls.
It maybe a slow process but it does do the job well.
The caves in Oasis were indeed a model (built in max), however as I recall the caves in fueldump were still brushes. Sock will be able to tell you the specifics on how they were made.
Personally I think it’s far quicker and easier to model them than it is to try and build it with brushes, but of course it does require you have knowledge of a 3d package. Really all you are doing is extruding an ngon shape along a path and then finally jiggering about vertices so that you get a rocky uneven look.
-Fluffy_gIMp
The caves/rockwork in Fueldump were all hand made with brushwork because I have a really easy system for creating rock. The whole cave system was made and detailed in a week and was heavy influenced by the original cave designs in RTCW. I also worked on the caves in MP_rocket which again helped my system for creating rock. As when I get some time free I will sit down and explain it in a tutorial so others may find it useful.
The caves in Oasis are indeed a Max model and during production it caused no end of problems due to clipping issues. Initially the cave where manually clipped but it was removed in favour of autoclipping via the compiler.
Sock
:moo: