Summary
I’m seeing what looks like an animation evaluation or bake regression specific to UE 5.8. The same animation data is correct in 5.6 and incorrect in 5.8, across multiple independent steps.
Character animated in Sequencer using Control Rig (tested on both a MetaHuman body rig and the standard UE5 Mannequin / Quinn).
A two-handed prop grip is set up using a Control Rig constraint (left hand IK control constrained to the right hand control). The prop is attached to the hand bone via a socket in the actor Blueprint.
IK stretch was disabled on the rig to rule it out.
What happens:
In the Sequencer viewport in 5.8, everything is correct — no stretching, hands grip the prop perfectly, prop sits correctly.
After Bake to Anim Sequence in 5.8, the result is wrong: on the MetaHuman the body is slightly stretched (scale values appear on the arm and finger bones, but not on spine/legs); on Quinn the body is fine but the hands no longer sit on the prop correctly. The constraint was baked to keys first (every frame, no key reduction) and verified correct in Sequencer before the anim bake.
If I take that same baked animation and bring it into a 5.6 project, it displays correctly — no stretching, hands correct.
If I then export that animation from 5.6 and import it back into 5.8, the offset returns. Same file, same skeleton, only the engine version differs.
So the issue is not in the source animation, my setup, or the bake settings — it reproduces purely as a function of the engine version. 5.6 evaluates/imports the animation correctly; 5.8 does not.
Reproduction is the key point: identical animation asset, identical skeleton, correct in 5.6, offset in 5.8 — both after a 5.8 bake and after re-importing a known-good 5.6-exported asset into 5.8.
Questions:
Is this a known evaluation/bake regression in 5.8?
Has the Mannequin reference/bind pose, or translation-retargeting defaults, changed between 5.6 and 5.8 in a way that would shift imported animations?
What Type of Bug are you experiencing?
Animation
Steps to Reproduce
- In UE 5.8, animate a character in Sequencer using Control Rig (reproduced on both a MetaHuman body rig and the standard UE5 Mannequin/Quinn).
- Set up a two-handed prop grip via a Control Rig constraint (left hand IK control constrained to the right hand control); prop attached to the hand bone via a socket in the actor Blueprint.
- Disable IK stretch on the rig (to rule it out).
- Bake the constraint to keys (every frame, no key reduction) and confirm in the Sequencer viewport that pose, grip and prop are all correct.
- Right-click the binding and choose “Bake Animation Sequence”.
- Play back the resulting baked Animation Sequence on the same character in the same 5.8 project.
Expected Result
The baked Animation Sequence should match the Sequencer viewport exactly. The character should not be deformed and the hands should stay on the prop in the baked result, identical to what is shown live in Sequencer before baking.
Observed Result
In the Sequencer viewport in 5.8 everything is correct: no stretching, hands grip the prop, prop sits correctly.
After “Bake Animation Sequence” in 5.8, playing back the baked Animation Sequence in the same project is wrong:
- On the MetaHuman: the body is slightly stretched, with scale values appearing on the arm and finger bones but not on spine/legs.
- On Quinn: the body is fine but the hands no longer sit on the prop correctly.
The baked result does not match the Sequencer viewport, even though the constraint was pre-baked and verified, IK stretch was disabled, and the bake used every frame with no key reduction.
Additional evidence that the source data is correct and the fault is in 5.8’s bake/playback: the very same baked animation displays CORRECTLY when opened in a 5.6 project. (And if exported from 5.6 and brought back into 5.8, the offset reappears — pointing to 5.8 evaluation rather than the animation data.)
Affects Versions
5.8
Platform(s)
Windows