3D viewer for more complex objects
Something like a 3D preview would be insanely helpful in this tool. An example of this can be found in MC Texture Studio:

I'll look into a loader for vanilla models (and may as well support basic OBJs as I've already written code for 'em in another project), after properly learning how the system works, though it won't instantly support some Forge flags, as there are a few shortcuts that I'd need to look into
The system will require LWJGL, as they have an OpenGL panel, though only in LWJGL 2, which requires more setuup with native libraries. For LWJGL 3, there's a third-party library, though the last I tried it, Gradle would stop recognising my project, so it might not be in tip-top shape at first
Attempting again to use lwjgl3-awt, I'm getting hit with errors. I've submitted an issue for it. I'll push the beginnings to a branch and continue when the issue is resolved
That issue was resolved, so I set up a plugin for it, but now I'm getting this issue, so I'll have to put this on hold until then. I might see about writing a model viewer with Swing, but it'll probably be quite a bit slower than an OpenGL alternative