Retargeting UE4 weapon animations to MetaHumans accurately

Development Character & Animation
1

Hi everyone,

We’re currently using UE 5.7.2 and still working with the UE4 mannequin skeleton. We have around 1,000 custom animations authored for it and want to move to MetaHumans in the future without losing that animation library.

Almost all of these are weapon animations involving the fingers, hands and arms. Accurate positioning is essential for weapon grips, reloads and interactions between both hands. Getting something that looks roughly similar isn’t enough.

I’ve spent a long time looking for a working solution and have followed numerous guides. Many give conflicting instructions, and none have produced the results we need so far.

I’ve been testing UE4-to-UE5 retargeting with RTG_UE4Manny_UE5Manny, including adjustments to the IK setup and Pin Bones. However, the hand positions already visibly differ from the source in the retargeter preview, and the hand IK isn’t transferring as expected.

Retarget
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Has anyone successfully transferred precise weapon animations from the UE4 skeleton to MetaHumans?

I’m particularly looking for guidance on:

  • The correct retargeting workflow for UE 5.7.2.
  • Preserving hand placement, finger poses and the relationship between both hands.
  • Correctly handling ik_hand_l, ik_hand_r and ik_hand_gun.

A working example or a current step-by-step guide would be extremely helpful. With this many animations, we’re looking for a repeatable workflow for the entire library.

Thanks for any help!