Page MenuHome

FBX: non-uniformed inverted-scaled bone breaks transform matrix on export
Closed, ArchivedPublic

Description

System Information
Operating system: Apple macOS Mojave
Graphics card: Intel Iris Graphics 550 1536 MB

Blender Version
Broken: (example: 2.80, edbf15d3c044, master, 2018-11-28, as found on the splash screen)
Worked: (optional)

Short description of error
the weapon bone that is a child of the character's root bone gets rotated by 180 degrees on the y-axis when I export the blender file as an fbx. The bone gets rotated inside blender as well as in the fbx file


Exact steps for others to reproduce the error
Based on the default startup or an attached .blend file (as simple as possible).

Details

Type
Bug

Event Timeline

Brecht Van Lommel (brecht) renamed this task from character bone get rotated in blender when I export the character's armature/mesh/animation as on fbx to FBX: character bone get rotated in blender when I export the character's armature/mesh/animation.
Bastien Montagne (mont29) renamed this task from FBX: character bone get rotated in blender when I export the character's armature/mesh/animation to FBX: non-uniformed inverted-scaled bone breaks transform matrix on export.Mon, Sep 9, 2:39 PM
Bastien Montagne (mont29) closed this task as Archived.Mon, Sep 9, 2:41 PM

Am fairly sure there is nothing to be done here, your bone has a non-uniform negated scale along the Y axis, that kind of things are known to be impossible to properly represent with a single matrix transform (which is a mandatory step in FBX exporter's animation baking process). In general afaik this should be avoided in rigs anyway (and even in regular objects' transformation), this always back-fires at some point.