Follow up to previous post - issue now 100% determined.
  • Scaling a bone in y axis (along bone length) that is a bone for a physbone root transform will cause physbone Jitter.
  • This was introduced with the update that made boops public. Avatar was previously fine.
  • Tested on multiple bones (ears, whiskers, hair, tongue) on a fresh upload default Awtter avatar, as well as another avatars ears - issue was repeatable in both avatars.
  • It appears to be only the Y axis.
  • I have not tried negative scaling values.
  • physbone parameters not at fault. Impossible to get natural motion and eliminate jitter.
  • Jitter frequency is high in VR, and less noticeable in desktop mode.
  • See attached video of issue replicated on all root transform bones on Awtter.