Bug report: VRMA bone matrices incorrect

[tdw46]

Describe the bug

With the attached VRM file, and VRMA made using the same rig in VRM Posing Desktop, import of VRMA does not produce correct bone transforms. VRM Files BONES ONLY.zip

Also, with the below VRMA made using blender. Playback is not right on the same rig inside unity/VRM Posing Desktop. But is correct when re-importing VRMA to blender on the same rig: ANIMATION FILES BONES ONLY.zip

• I included a video and a glb of what the animation is supposed to look like: https://github.com/user-attachments/assets/d0963acd-737c-4058-81f6-c8898aff0e03
• Versus what it ends up looking like in a Unity based app: https://github.com/user-attachments/assets/6e8fc3ad-688b-4d63-91cf-ac5bd98acd12

To Reproduce

1. Export VRMA of attached VRM above from Blender, and try to load in a Unity based application like VRM Posing Desktop. Pose will be wrong.
2. Export VRMA of attached VRM above from Unity Based App like VRM Posing Desktop, and try to load in Blender. Pose will be wrong.
3. Export from blender and reimport into blender and things will be correct. Export from unity and reimport to unity and things will be correct.

Expected behavior

Animation transforms should work the same in any app that is using the VRMA standard correctly. It seems there is something not working for this particular rig that might indicate a larger problem with the blender exporter/importer.

Desktop

• OS: Windows 11
• Blender 4.2
• Addon Version: 2.20.82

[saturday06]

Thanks for reporting!

This is a bug and will be fixed in a future version.

[tdw46]

Thanks for reporting!

This is a bug and will be fixed in a future version.

May be related to the work you'll need to do on this. It looks like all actions in my blender file are exporting on my VRM:

Would be really nice if we can just expose the gltf settings under the advanced section of the exporter so power users can turn on/off standard gltf features (that aren't part of VRM Extension).