Mixamo animations: looking for methods on how to make arms not adhesive to the torso

Besides the issue of me being very new to Blender, it took a few hours of toiling with multiple downloaded versions of Blender (I downloaded three versions just to get this right) and a lot of research just to finally be able to import Mixamo animations. They look really good!

My one problem is just the positioning of the arms and the legs. The way they bend feels rather unnatural and the arms all seem to want to bend inwards from the shoulder and stick right to the body’s sides. Besides editing all keyframes manually which might seem like a pain, I’m not sure how I can get the arms to look more natural and not, well, twisted like this.

For the record, I’ve tried many different things, including just exporting the armature and using it as the Mixamo animation preview character (auto rigs). Previewing animations on just the armature actually shows the intended effect I’m looking for. Notice how the arms do not bend inward on the armature unlike how they bend on the full figure in the picture above.

Any help on how I can get my rig to follow the same motion as the armature?

Included below is all the files I am currently using. There are rigs, the armature as well as cleaned FBX animations that can be loaded onto a rebuilt rig and exported.

BlenderTest.zip (661.5 KB)

CleanedAnimation* files are FBX animation data that can be imported to a rebuilt rig. ExportedR15Rig is the fully exported rig (all export items selected) that I give to Mixamo before picking and downloading an animation. R15Rig is the exported rig from Studio that can be rebuilt with the Blender animation plugin. R15RigArmatureOnly is an exported FBX that can be given to Mixamo to see the animation previews which, when played on the armature, differ from exporting everything else and then importing the animation data back after cleaning it up (Mixamo renames bones for some reason if you export everything, but exporting just the armature does not do that).

Would appreciate any help!

P.S. I’m not sure if it’s better to just import the armature that looks proper? Usually if I do that it doesn’t work; importing via the N menu doesn’t apply the animation and using map keyframes by bone name provides me with an error about an active attribute. These are unsolved on the Blender importer thread itself so I’ve opted to ignore it.


Well, in my experience, I will say that the problem here is in the character of roblox. All animations in mixamo are MoCap. And they are designed for a different type of character

I mean, for example, the r15 character has only one bone in his back. And the animations in mixamo are designed for 3 or more

Thank you for the response but this does not answer my question nor provide any substance beyond repeating what I already know which is that yes indeed it’s a problem with the rig itself. I’ve identified the problem but do not know how to fix it.

As shown in the media attached to the thread the animations are capable of being rendered on a Roblox R15 rig. My problem is not that the animations do not show or that there is a different bone count between the rigs shown in Mixamo and R15 but rather that the arm bones are twisted inwards.

I have the information in the thread and you’re welcome to give it a read over again to provide a more informed response, or none at all if not applicable. Thank you!

1 Like

Does the issue persist with any animation - and if so, does it always appear in the same way? My team and I are currently trying to get Mixamo animations and/or other motion-captured animations to work ourselves, but have had different issues regarding deformation than the ones you showed.

1 Like

I haven’t tried a wide variety of animations nor this method in a couple of months since I gave up on trying to import them, but as far as I’m aware the issue still persists. The bones seem to bend inward whenever importing any animation but they’re fine on the raw armature.

After looking at the rig you sent, it should work with mocap - it may be the specific animation you were using. Any chance you can send the .blend file with the weight painting included? Might be able to get you a tweaked version that’ll work properly for your use case.image

Sorry - I don’t have a blend file on hand. I’ve mostly just been importing the files in the BlenderTest zip back into a new project whenever I attempt the animations again or creating a whole new rig from scratch. All the files I use are included in the zip sans any blend files.