Is it possible to manipulate/move/delete vertices in a generated model (created using X_OBJADDVERTEX etc.) using GLB or will I have to create all of my (simple geometric shapes) models in a 3D drawing program (AC3D) and every single frame of animation by hand?
you can get the information of a mode with X_GETFACE. And with X_STARTOBJ/X_ADDVERTEX you can build objects (no animations so far, though). So, you can write a program to create an altered copy of an object.
Aha, ok thanks that's what I wanted to know. That should do just fine. Thankfully it will be mostly simple geometric shapes. :)