Arms crossing after Rokoko retargeting (Xsens BVH → Mixamo rig), even though both source and target are confirmed T-pose
Hi everyone,
I’m running into a retargeting issue in Blender using the Rokoko plugin and could use a second pair of eyes.
Setup:
- Source: a BVH mocap file recorded with an Xsens Link suit. I’ve confirmed that frame 1 of the BVH is a clean T-pose (arms horizontal, palms down).
- Target: a custom character that I rigged and auto-generated with Mixamo. I’ve also confirmed the character’s armature is sitting in a proper T-pose in Edit Mode / rest pose.
Problem:
When I retarget the BVH animation onto the Mixamo rig using Rokoko’s Retargeting panel, the arms cross over the chest during playback — a scissoring effect on the shoulders/upper arms. I’m new here and can’t upload attachments yet, so I’ve shared a .blend file via Dropbox in case anyone wants to take a look directly:
In the .blend file:
- The rigged character armature is named Armature.
- The mocap BVH armature is named Bodypack_2_0.
- I removed the already-retargeted animation from the file, so it just has the character and the mocap source — the crossing issue happens once you retarget them together with Rokoko.
What I’ve already tried:
- Confirmed both armatures are genuinely in T-pose before retargeting (not A-pose or N-pose).
- Switched Rokoko’s “Use Pose” option from Rest to Current, with the playhead parked on the BVH’s T-pose frame, then rebuilt the bone list and retargeted again. No change.
- Double-checked the bone mapping list generated by “Build Bone List” — as far as I can tell, left/right arm bones are mapped to the correct sides.
Since the rest pose alignment seems fine on both ends, I’m suspecting either:
- A bone roll/twist axis mismatch between the BVH-imported skeleton and the Mixamo rig (Blender’s BVH importer doesn’t always generate anatomically consistent roll values for diagonal bones like the upper arm), or
- An axis/orientation issue from the BVH import (Forward/Up axis settings) that’s flipping the shoulder rotation sign without visibly breaking the T-pose.
Has anyone dealt with this specific Xsens → Mixamo combo in Rokoko? Would appreciate any pointers on where to check roll values or whether there’s a known offset needed for Xsens-exported BVH skeletons specifically.
Thanks in advance!
