In a nutshell, the GLTF module works like this:
structures/
folder contains GLTF structures, the
small pieces that make up a GLTF file, represented as C++ classes.extensions/
folder contains GLTF extensions, which
are optional features that build on top of the base GLTF spec.GLTFState
holds collections of structures and extensions.GLTFDocument
operates on GLTFState and its elements.editor/
folder uses GLTFDocument to import and export 3D models.