My problem is that the file structure doesn't look like it supports that as every potential airline option is simply a config with ref data to a logo. Since I'm starting from scratch so to speak, I'm just wondering if this is even possible.
The file structure supports *everything*, it's just that most of the vehicles config files are organized in a way that it would be easy and efficient to just change the logo, in order to allow hundreds of operators AND to allow automatic generation of all the SIM.CFG files, for example to add/change a new operator.
But GSX can use any vehicle, even something that was made with an entirely different file structure, as long it has a correct [Couatl] section in the SIM.CFG that will indicate GSX-specific information about the vehicle kind and some of its GSX-specific parameters. But other than the [Couatl] section, the rest of the SIM.CFG file is 100% FSX SDK standard, so it's just another FSX vehicle, so the file structure rules and how you make aliases and fallback to other folders, don't change.
We haven't offered a "layered" PSD PaintKit, because most of the times, we never used one ourselves. For the absolute maximum efficiency, in many cases, the textures are NOT human-generated, so there weren't any layered .PSD file to start from.
We use a technique known as "texture baking": the original model in 3DS Max might have used dozen of different materials, and even materials not compatible with FSX, and these might have used a large number of original .PSD files. But thanks to texture baking ( look for "Render to Texture", there are many tutorials on YouTube explaining how this works ), before the object is exported, many materials will be combined into a single texture sheet, with chunks of pixels belonging to parts of the original material/s all "messed up", something that nobody could come up with if drawn manually, also because pre-rendered shadows from ambient occlusion would be added to it, all in a single texture (or two, at most)
The main advantage of this, is that we have the utmost efficiency from the models, because they only use 1-2 materials at most and very few textures, which allows for almost no fps hit caused by GSX vehicles.
The downside, is that, other than the logo, it's not really possible to create an easy to used layered .PSD file that would allow you to customize the *whole* vehicle appearance, because the final textures are computer generated and are a big mess to look at. Not all vehicles use this method, but most of them do.
