Things you'll need if nobody else is putting out content, to paraphrase something DS has said time and time again over the years, "Want something done learn how to do it yourself!"
1. 3d modelling software. It's expensive, for example 3ds max is something like 189 bucks a month for a subscription. Not realistic as it does not pertain to my job.
I recommend Blender, it gets updated frequently. While not intuitive in the least, and I myself have spent years trying to get even a basic grasp of it, it is powerful, modifiable, covers many 3d formats, and is best of all, free.
2. Photo editing software. Adobe Photoshop is one of the best, but again, like 3ds max is super expensive and I can't afford it. One cheaper program I opted for was CorelPaintShop Pro x5 (they're up to x8+ now), as it was only 50-60 bucks on sale at the time. Alternatively there is always GIMP, like Blender, it's not super intiutive, and the older versions I've used the floating undocked windows are a huge pain and not very intuitive. But like blender it's free, updated frequently, and can do most if not all the more expensive programs can do.
3. Optech, or Jeremy's XWA opt editor. I personally prefer the latter as I have had zero luck historically with Optech, for whatever reason.
4. Patience and either a surplus of time to get good fast, or spend the better part of a decade figuring out how these programs work, and how an opt goes together. (I still maintain I barely know how myself)
Okay. So realistically my modelling skills are poop. I'm a novice. Scratch building has never been my forte in any medium, but using various existing components of other things, I have been able to make new things. Legos have always yielded good results for me historically, and I've found I am better at modifying existing assets than creating from scratch when it comes to computer based art or code work. That said, I'm branching more into scratch modelling and texturing as I gain familiarity with the tools, and my latest project that have yielded results has both increased my familiarity with the Opt creation related tools, a very basic understanding of how a 3d model goes together, and what limitations are involved in the process.\
Point of reference, my first "opt" was the Z98 "Corsair" I mashed together in Optech accidentally by loading both ships into the same file. Then DTM for some reason actually liked the concept, and made a better version using my concept as inspiration. Incidentally, the similarity to it and the ARC-170 is kind of hillarious, but I don't recall if ATOTC was out at that point.
Disclaimer aside on my abilities, I'm going to jump into things.
This is my process.
1. Decide what hangar to make. This usually is spawned by either boredom, or incidental to a mission arc I'll likely never finish, let alone start.
We'll use the Strike Cruiser for this example. Technically you could probably get away with cloning the Calamari Hangar since it's similar, but I just noticed that it is in fact significantly more different now that I actually examine it.
2. Ensure that the Original optname.opt is in a folder within whatever your project folder hierarchy is. IE Blender Working files > (Optname) Hangar > Optname.opt.
2a. Load up XWA opt editor, import the opt, and then immediately export it as an .obj file.
2c. All your textures and the new .obj and .mtl file should be in that folder you set up.
Note: if you fail to isolate your files you will conflict with any other projects you are working on by either overwriting files each extract, or simply have no sense of organization.
3. Now that that is done, load up Blender.
3a. Import your optname.obj file.
3b. Find out what is visible from inside the hangar, and what you would expect from the out looking in camera angle.
3c. Delete all non-visible meshes from the original opt.
4. Go through step 2 with the CalamariHangar opt, ie Hangar.opt
5. Import the Hangar.opt into your blender instance that has your modified opt open.
5a. check to ensure that the opt you are modifying has the relevant parts of the model, such as hangar opening if relevant, and especially the floor and back wall aligned roughly with the calamari hangar you've imported.
Note: This may require resizing, or relocating your model relative to the calamari hangar; do not relocate the calamari hangar relative to your modified opt, it won't go well for you when your player craft is behind the wall.
Screenshot 2018-03-24 13.41.16.png
Also note that it isn't necessarily relevant to have the hangar opt be identical to the parent ship dimensions since you only ever see it in an isolated environment. My general rule of thumb, is that it has to look good and have no clipping. Depending on the size of the ship though you will have to take into consideration what kind of ships you intend to put in there, and whether or not it would make sense for those to be in the hangar of a smaller than capable ship of containing them in the first place.
6. Once everything is set up the way you like it relative to the calamari hangar. Delete the calmari hangar meshes.
Screenshot 2018-03-24 13.41.05.png
7. Save and then export your modified hangar opt as an .obj file
8. Reload it into XWA Opt editor. If you did everything right it should load up fine. If not, go find out what you broke. I find that it's usually an incompatible texture format like .tga or .dds I missed somewhere in the event that I'm using a model from another game format. However, if you're modifying an existing opt, this should never be a problem.
9. Set the meshes to whatever relevant type they need to be, and assign hardpoints for Hangar in/out and Accel start/end points.
10. Load up hangar in Jeremy's Hangar Editor and customize what interior items you want to see.
Screenshot 2018-03-24 13.52.13.png
11. Play the game with your new hangar(s)
It's a really quick and dirty tutorial I did up in about 5 minutes, and as I already had this particular hangar finished, I merely staged the screenshots in blender, in case you are wondering why it looks a little exaggerated, and I did not post as many screenshots as I was planning on it due to only being able to load up 3 attachments per post. But I figured it's a simple illustration. I can make this a multi-post if you need more clarification.