Gltf-blender-io: Scaling issue when non normalized quaternion

[torbenvanassche]

Describe the bug
Mesh scale is weird when exported glb from blender.

To Reproduce
Steps to reproduce the behavior:
Export mesh from blender as gltf
Scaling is wrong(?) on export

Expected behavior
Export sucessfully with shape keys as morph targets for threejs

Screenshots

.blend file/ .gltf
scene (2).zip

Version

• OS: [e.g. macOS, linux]
• Blender Version 2.82.7

[donmccurdy]

The scale looks the same in both places to me:

blender

threejs

Note both are about 6 units across. Could you explain what you mean by "scale is weird"?

[torbenvanassche]

there is a mesh 3d printer in that gltf file scene. thats the only one so far that has shape keys.
I do understand my explanation was kinda subpar. bottom right corner the mesh is really not as it should be. I had the object in question highlighted in blender but I should have been more clear

[donmccurdy]

Hah ok I see it now, thanks! We'll take a look.

[julienduroure]

Ok, find the root cause, and I am able to reproduce on simpler scene:

This is linked to a non normalized quaternion rotation on your 3D printer (object with parent having a scale)
Change 3D printer rotation from:

To:

Will solve the issue

[torbenvanassche]

I'll confirm that worked and fixed it. Thank you for the (especially fast) help.