I used an identical process to import the character and retarget the animation.
I realize that a manual retarget will resolve, but it is definitely worth reporting, and wondering if anyone else is experiencing this.
I assume something has changed with the actual bone structure in the Metahumans (not likely), or the automatic retargetting feature in 5.6 is unfinished or changed.
Even if you export the third-person SK mannequin from 5.6 to reimport it under a different name and then try retargeting on the SK mannequin, thus using the same names on both sides, it won’t work. You’ll get this error message: “IK Retargeter bone chain, Root, was unable to be normalized. Chain too short.”
I tried this after cloning a project and found that all my animations were broken, since even those that had been retargeted on a previous version will be broken again at the hand level.
It’s currently not possible to use these functions, at least I haven’t found them yet; I think we’ll have to wait for a patch.
I was able to retarget Rokoko mocap animations to the Metahuman 2.0 character skeletal mesh in 5.6 without issue (besides the usual clean-up etc.). Need to test again with Mixamo animations though.
