I take it you want some guidance? The main thing you need is this:
a .veh file
a .npc file
a *rider tag
Actually, that's about all you need (especially for non-animating vehicles like swoops and TIE-Fighters). If you want it to have exhaust and be able to fire weapons, you need some extra tags like
The best way to see all of this is to look at an example. The .veh files are in ext_data/vehicles. The .npc files are in ext_data/npcs. Both are editable with any text program. The vehicle model is in the models/players directory in the folder specified in the .veh file. The vehicle model is viewable with our ModView model viewer program. I suggest checking all of these files out to see how it all goes together.
A good guide to the .veh files is the template.veh file in ext_data/vehicles. It explains what each field does.
The same goes for vehicle weapon files (.vwp files) in ext_data/vehicles/weapons. Check out the template for an explanation.
All you really need is a vehicle model (in .glm format) that's the proper scale and has the right tags. Someone could easily make an A-Wing or TIE Interceptor vehicle if they already have a model to use. MilkShape can import tons of model types and export an md3. You can then load the md3 in MD3View and export it from there as a .glm (ghoul2 model).
As for animal-type vehicles, all you need is the .npc, .veh, *rider tag and proper anims. You don't need to make all-new anims, you can just re-map existing anims to the needed vehicle anims. Check out the rancor and wampa animation.cfg files to see how I did this, as a test (note the rancor and wampa vehicle files - there are no rancor and wampa vehicles in the game, but I did those as a test to see how easy it is to make new animal-type vehicles). Using this method, you could convert any of our NPCs into a vehicle (imagine riding a droid or Stormtrooper around!)...
Once you've made your own vehicle, you can place one in the map by placing an NPC_Vehicle and setting it's NPC_type to the .npc file's name of the NPC vehicle. Or you can spawn it from the console by typing:
\npc spawn vehicle <npc vehicle name>
Without the "<" and ">"...
Good luck and have fun!
Michael Chang Gummelt