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Root motion does not transfer from mixamo character (bug?)

I have mixamo fuse character with simple root motion animation (running forward). The character has “root” bone.

Here’s the thing - when I attempt to transfer that animation to any other character (including unreal 4 dummy skeleton), the root motion bone movement does not transfer and is set to zero. No rotation, no location, nothing. Animation transfer is done using Unreal 4 builtin motion retargeting system.

Original character is correctly mapped to humanoid skeleton, root bone is selected in retarget manager. Despite that, root motion doesn’t transfer, regardless of the state of “use root motion” checkbox, and changing animation retargeting mode (Animation from drop down menu doesn’t do a thing.

How do I fix this?

Still looking for some kind of response/info on the subject.

As far as I know mixamo dont have root bone, so which bone are you assigning to root bone in ue4 skeleton?

They do, if you create character in fuse, and upload it to their autorigging service. In that case animation will contain root motion and “root” bone. I’m assigning “root” bone as Root.

is the root bone at 0,0,0 ? Cos I had a look into mixamo rigs in maya and their root bone is the hips bone, which is quite wrong if you ask me.

Yes, it is at 0,0,0 and it is animated. As I said, if you’re looking at mixamo characters (alpha/beta/zeta/whatever), you’re looking at the wrong place.
It is mixamo fuse character. Mixamo fuse is character generator. The bone chain goes like this root->pelvis->spine_01->spine_02->spine_03, etc.

The only problem is that its motion does not transfer during retargeting process. At all.

I think it depends on what options you download them with… It does start with a root bone in this order root → pelvis → spine1-> spine2-> and so on.

Animation retargeting is done using unreal tools (Animation Retargeting (Different Skeletons) | Unreal Engine Documentation).

The PROBLEM is that original animation has root motion, new retargeted version doesn’t have any root motion in it.

So, there’s no issue with mixamo animation. The problem is with retargeting process (root motion information is lost). And I’d like to know how to deal with this.

I was using unreal tools for retargeting Kubolds animations (they have root motion for sure) and I had no problem with this process. Can you post a screenshot of your original animation with pointed root bone?

Which version of the engine? Can you confirm that the process still works without any problems for you?

See attachments.

Animation is used with root motion enabled, but I provided one screen with check box turned off just to show that there’s motion.

When I try to retarget that to anything, motion from the root bone does not transfer and is set to zero.

To be honest, this animation looks correct. I was retargeting with UE4 4.8

Are you planning to retarget anything with 4.10 in near future? Would be nice to see if it works for someone else with other animations.

If it doesn’t, I guess it’ll be the time to file bug report.

Ok, I have tested it in 4.10 and you are right, there is a bug.
The translation is of root bone is not applied. The rotation is ok.

So feel free to report this as a bug. In meantime you can get the older version of ue4 (as I wrote, I was using 4.8 and 4.7 for this) and do retargeting there.

Okay, thanks for the testing. I’ve reported the bug on answerhub.

What’s that supposed to mean?

Since apparently nobody knows how to deal with this, I’d appreciate if someone would at least tell which part of the engine handles actual retargeting process. So I could look into that without wasting time trying to locate it first.

have you checked out this epic tutorial series about skeletal assets?

I know how to retarget animation, the thing is the animation retargeting process is broken as of 4.10.

There’s a bug related to that too: JIRA [UE-23809]

Right now I’m simply asking if anyone knows which portion of the the engine handles that.


Actually, nevermind. It is wrong section for coding-related question.

I’ve just encountered the same problem.
I’m going to check if it isn’t broken in 4.9/4.8. If not, maybe we should try something like this as a workaround:

  1. Create a new 4.8/4.9 project (depending of which version root retargeting isn’t broken) and migrate all the animations we want to retarget (ofc along with both skeletons) there.
  2. Retarget it in the 4.8/4.9 project and migrate retargetet animation into our 4.10 project.

I’ll try to do something like that today.

… Or maybe they already fixed this bug in 4.11? But there’s still no response on AnswerHub reports.

Edit: Well, animations won’t migrate to 4.8. That’s about it regarding my mighty workaround :stuck_out_tongue: I’ll try with 4.9 (and maybe 4.11) though…
Edit2: Also, can’t migrate back into 4.9. Now I’ll try 4.11 Preview…