message: gltfpack: Fix crash when processing meshes without materials
  The quantization data for texture coordinates can't be initialized for
  meshes without materials. Since we're not going to output texture
  coordinates for such meshes anyway it's safe to skip it.
diff: @@ -1458,6 +1458,9 @@ void prepareQuantizationTexture(cgltf_data* data, std::vector<QuantizationTextur
  {
  const Mesh& mesh = meshes[i];
  + if (!mesh.material)
  + continue;
  +
  size_t mi = mesh.material - data->materials;
  assert(mi < bounds.size());
  