Importing mesh loses hierarchy

Hi,
I noticed that if a mesh with children is saved with SceneSerializer it loses the hierarchy when it is loaded.

I have build this examples for show the problem:
Export playground
Loading with AssetsManager
Loading with SceneLoader

I also notice that exporting doesn’t work if a mesh doesn’t have a material:
Export meshes without material

Sorry we didn’t answer earlier, and thanks for reporting this, I’ve opened a PR with fixes :smiley: Fix scene serialization and loading issues. by carolhmj · Pull Request #12856 · BabylonJS/Babylon.js (github.com)