Does all operations are lossless?

[necros2k7]

ie. gltfpack -i 1.gltf -o out.gltf
-tc -tu -tq -mm options?

[zeux]

By default gltfpack uses quantization on all geometry components which is a lossy process. You can disable it with -noq, which will leave geometry operations that are lossless (although this is not recommended because it increases file size / memory impact).

By default gltfpack doesn't compress textures, but when -tc or other texture options are used, it uses Basis Universal format to compress textures which is also lossy.

-mm and -mi are lossless as they just transform draw data to reduce draw call count.