Here's what I did for the Galactica model (which was originally a SFC I MOD file). Before we start, I want to say that I am NOT a 3d modeler, and it's not only possible but very likely that there are much more efficient ways to do this. It's also possible that I'm leaving a step or two out, so anyone who does this on a regular basis, please check my math and correct me where I'm wrong:
Find the MOD file for the ship you want (try a google search for SFC mesh or SFC Mod if you're looking for stuff)
Download Milkshape 1.6.6 (NOT the 1.7 beta) from
here.
To to
http://www.starfleetuniverse.com and download the SFC plugin for Milkshape.
Get Lithunwrap from here:
http://files.seriouszone.com/download.php?fileid=198
Import the MOD file of the ship you want into Milkshape. Edit>Select all. Rotate X -90. Face>Reverse Vertex Order. Scale (I've found that anywhere between 6 and 12 is good). Save as: Autodesk .3ds.
Now, open the .3ds model in Lithunwrap, select the individual Groups, and move them around and scale them until all the Groups fit in the large gray box on your screen. Under the Materials tab, delete all but one (Starfury wants one texture map only). Model>Save>Save as Direct X (Text, uncheck Compression) in the X files directory of Starfury. Click Copy UV Map to Clipboard and then open up a new document in your trusty image editor (I use Photoshop myself) and paste the UV map there. Now, open up all the .bmp files that are associated with the model (They're the .bmp files that come with the model). Select all>copy>paste each of them onto the UV map, scaling and moving them so that they line up with the lines on the UV Map (I find that altering a layer's opacity helps). Flatten layers, resize to 256 x 256, save as a .bmp to the images directory of Starfury.
Now, back at LithUnwrap, click on the materials bar you left alone, rename it to the .bmp file you just saved, click properties, under Diffuse Map, choose Map: bitmap, then Properties, Change, and load the .bmp. Click View>Material and select the material; it should show up within the gray box now. Click Preview>Show Model and make sure everything is Ok. Save as .x to the XFiles directory. That should do it.
Now, it's just a matter of editing the SpaceObjects_XFiles.txt file to get your model in there.
You should be able to use more or less the same proceedure to import Bridge Commander models, Homeworld models, etc, although I haven't tried this yet. Good luck!
Oh, also, for ship layout files and shield layout files, you can't go wrong with a visit to
http://www.shipschematics.net