When a new option -kv is specified, gltfpack no longer removes unused vertex attributes (v mirrors existing usage for -sv and -vX).
This can be useful in a few cases:
Normals may be needed for custom vertex processing even if materials are unlit
Tangents may be needed for custom shading at runtime that gltfpack isn't aware of
Tangents may help with simplification across UV mirroring seams
Texture coordinates may be needed at runtime even if this is not indicated by any material textures; in this case, -vtf should be used to disable UV quantization
When a new option
-kvis specified, gltfpack no longer removes unused vertex attributes (v mirrors existing usage for -sv and -vX).This can be useful in a few cases:
Fixes #715.