Debugging VRM support

[madjin]

I have been mostly following ifire's changes to add VRM support: zeux#199

Steps to reproduce and test

git clone -b vrm-opt git@github.com:madjin/meshoptimizer.git
cd meshoptimizer
git clone -b gltfpack https://github.com/zeux/basis_universal
cmake . -DMESHOPT_BUILD_GLTFPACK=ON -DMESHOPT_BASISU_PATH=basis_universal -DCMAKE_BUILD_TYPE=Release
cmake --build . --target gltfpack --config Release

after compiling gltfpack, can run it on the sample VRM like so:
./gltfpack -i 225.vrm -kn -km -ke -tc -cc -si 0.5 -o 225_ktx_1.vrm

then to debug, the files I changed are these:

gltf/main.cpp
gltf/gltfpack.h
gltf/gltfpack.cpp

Test with

• drag and drop VRM into hyperfy.io world
• https://vrm-validator.fern.solutions/
• Rename vrm to glb, then try https://gltf-viewer.donmccurdy.com/

Results

Everything looks good based on the various validators I tested, not sure what the issue is.

Errors

Error in https://hyperfy.io/

Error in https://gltf.report/

Error in gltf sample viewer: https://gltf-viewer.donmccurdy.com/

Intended Behavior

The exported VRM working in hyperfy / platforms that support ktx + meshopt (upstreet perhaps might too)