Animation not blending smoothly in UE 5.6.1 even though bones are matched

Development Character & Animation
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1

Hi everyone,

I’m running into a strange issue with animation blending in Unreal Engine 5.6.1.

My animation transition isn’t blending smoothly — it looks like it snaps abruptly instead of blending, even though I’ve carefully matched the bones between both animations. What’s strange is that it was working correctly earlier, and nothing obvious seems to have changed.

Here’s what I’ve already checked:

  • Both animations use the same skeleton.

  • Bone transforms are visually aligned at the transition point.

  • Each animation plays correctly when previewed on its own.

  • I’ve double-checked the Blend Poses by Bool node and the blend time in the AnimGraph.

Things I suspect could be causing the issue:

  • Root or reference pose mismatch between the two animations.

  • One clip might have root motion enabled while the other doesn’t.

  • Retarget Base Pose may not be identical.

  • Possible issue with Layered Blend per Bone or bone filters.

  • Compression settings might have affected keyframes.

Has anyone experienced this in UE 5.6.1, where blending suddenly stops working even though bone alignment looks correct?

Any ideas, debugging tips, or things to check would be really appreciated.
I can share a short video of the issue if needed.

Thanks in advance! :folded_hands:

2

Hey!

I’ve run into this kind of abrupt animation blending issue before in UE 5.6.1, and it’s usually one of these sneaky setup mismatches even if everything looks aligned:

:white_check_mark: Things to Check:

  1. Root Motion / Reference Pose – Make sure both animations either have root motion enabled or disabled consistently. Also confirm they share the same retarget base pose (a small offset here can cause hard snaps).
  2. Blend Settings – Double-check the Blend Poses by Bool or state transition rules. Even a very short or zero blend time can look like a snap. Try increasing blend time slightly.
  3. Layered Blend per Bone – If you’re using this node, check that the bone filters are correct and that you’re blending the right hierarchy (missing branches can cause partial jumps).
  4. Compression Settings – Sometimes animation compression strips out critical keyframes. Try setting both clips’ compression to None to see if it smooths out.

In most cases, it ends up being either a root motion mismatch or a retarget base pose difference after an update or reimport. Reapplying the base pose or reimporting both animations usually fixes the issue.

Hope this helps! :victory_hand:
Let me know if you can share a short clip — it’ll make it easier to spot if it’s a bone alignment or timing problem.

3

Hello there @Himanshu_1995!

Checking around the community, this type of issue pops up from time to time, specially when Blender is involved. So, my very first question would be, were your animations created or modified in Blender? If so, I would reset import/export settings on both UE and Blender, ensure all transforms, modifiers and changes are applied before transfer, then re-import everything, while having compression settings offs, as you mentioned.

The next, most usual cause for this problem, is a corrupt or stale cache. To clear said cache, please close UE, go to your project’s directory, and delete folders DerivedDataCache, Intermediate, and Saved. After that, re-open the project, and recreate your blend node.

If the issue persists, then please check the setup for your suspects. Look for root bone/pose mismatch (both need to be identical), ensure that root motion enabled is either enabled or disabled on both pieces (having one on and one off will definitely results in a mistmach).

For further investigation, please check the following video guide on Blending.