Don’t forget to check if the chain mappings for the IK bones are properly mapped in your IK Retargeter asset.
Also, check if the retarget chains for the IK bones are actually set up in both the source and target’s IK Rig assets!
For some reason, it seems Epic removed the retarget chains for the IK bones, in the default IK_Mannequin IK Rig asset.
So, I had to re-add them myself.
Additional notes about my retargeting process:
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I’m using Unreal Engine v5.4.4.
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In my screenshots, I’m retargeting from the Mannequin (UE5 skeleton) to a VRoid/VRM character (VRM skeleton, imported using the
VRM4Uplugin).
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I used the
Free Bone Snapperplugin to snap the VRM skeleton’s IK bones to their proper positions (i.e.: their respective FK bones).
For more details, please refer to Free Bone Snapper’s documentation and video tutorial. -
For my specific retargeting setup (UE5 → VRM) to work properly, in the Bone Snapper (solver) settings, I used the following values:
Root Snap Bone Name = None
In Place = False
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In the IK Retargeter, I also used
Auto Align -> Align All Bonesbefore retargeting. -
You may have noticed the
Easy Posebutton in my screenshots, it’s from another plugin (by the same developer of Free Bone Snapper) I have installed in my project.
Just ignore this button, I foundAuto Alignto be a much more reliable option in my case.
