[Question] Clarification on Character rigging requirement

I would like a bit of clarification on character rigging requirements please.

We are planning on doing a VR toolkit that includes a male/female character as well as many other things. According to the submission requirements, humanoid characters submitted to the marketplace are to be rigged to the UE4 skeleton.

Do characters contained in a much broader toolkit, and not intended to be used by themselves, fall under this requirement?

Also, along this same line… the free Mixamo character pack does not use a UE4 skeleton. How does an asset pack like this fall into the requirements?


I’m also interested in this, mostly related to Mixamo. I’m interested in Mixamo-UE4 workflow, but how can this skeleton discrepancy issue be solved?

Another quick question: which is the “Epic Skeleton”? Is it the one that the blue-guy uses?


Good points! We’re working on expanding the submission guidelines ( to explain exactly what the Epic skeleton is, how to build meshes and animations which conform to it, and how UE4’s various animation retargeting features can assist with the process. And, we’re looking into updating the Mixamo animation pack to conform the humanoids to the Epic skeleton. It may take a couple of weeks to get everything sorted out!

Thank you Tim!

It would be incredible if there was, maybe in the future, some integration between Mixamo rigs and UE4 ones. More so with the new pricing tiers which are making the mixamo-ue4 pipeline much more attractive.

Thanks Tim.
Any ETA on when those new “Epic Skeleton” guideline updates might be available? Since we are working on a Marketplace submission it would be good to get a legit skeleton to work from as soon as possible.

As a preference I would like the FBX source. We use Motion Builder and with the source files its an easy job to retarget

Agreed, as soon as possible please!

Will we be able to give feedback on the proposed skeleton?



Seconded. Maybe a tool for converting both characters and animations between the two?

Hello, all,

We’re working on clarifying this issue and we also know that Mixamo doesn’t follow this guideline.

The guideline out there is what we use internally to make sure to keep animation sharable between different meshes.
The idea is that people can download any animation or any mesh and can play any animation on any mesh. In order to do so, we need to make sure the skeleton has same hierarchy because of lack of retargeting system in engine. We’re working on that now to improve it, and that is the highest priority on animation system but until that comes online, this is to support user experience.

This is by no means permanent. This is just a temporary resolution for us to support user experience of sharing animations.

We’re going to post soon about what Epic Skeleton is, but this is only for Market place. If you make meshes for your system, you do not have to follow this guideline. Until we have the proper system to share animation, we’d like to enforce more strict rule in exchange of a better user experience.

We sincerely apologize for this inconvenience. And we really hope to change this rule as soon as possible.


Hey everyone!

We’re getting all of the assets together now for the marketplace submission page. However, if this is blocking anyone, I’ve put the files HERE so that you can start modeling your characters to the skeleton right away.


I think you guys have very valid reasons for having that requirement and it makes perfect sense. I hope Mixamo can some how integrate the Epic skeleton into their pipeline so that is a resource that can be more easily utilized.

And thanks for the “early” release Jeremy! That is exactly what we need.

Thanks for the info Lina, and the files Jeremy.

If I import the FBX character into the Editor (4.4.1) and then load the included walk cycle there’s a gap between the shoulders and arms.

EpicTemplate Walk.png



I was want to plug my 3 cents.

I personally like this requirement, and hope it will never be lifted even when re targeting will be in engine. Retargeted animations always tends to look subpar compared to the native ones.

Hey Mark!

We’re going to add a skeleton asset to the engine as soon as possible that will have the correct defaults. My guess here is that on the skeleton asset for that mesh, the translation retargeting is set to ‘Animation’ instead of ‘Skeleton’ for the arms/legs. For most of our characters that share animation, we leave the ‘animation’ or ‘animation scaled’ settings for the hips, root, and any other leaf bones that may need translation(usually weapon bones and ik bones), and set most others to use ‘skeleton’ translation retargeting.


Thanks Jeremy,

Changing the retargeting fixes it.

I’ve done a couple of new animations and they’re fine. Got a decent workflow sorted out for exporting animations from MODO now.



awesome! Glad to hear it! Let us know if we can help any further :slight_smile:

Assuming this rig was created with the Maya A.R.T. scripts, is there a chance we could get the template for it? I already have models created in a relaxed t-pose close to the default model pose used by the Maya tool, and it would be fantastic to create animations packs for the marketplace using Jeremy’s tools as well. :smiley:

You already have it. Have a look at the Mannequin example that comes with A.R.T., it’s exactly what you are looking for.

If you ever do lift this requirement, please add in something to the marketplace to indicate what animations/characters use the standard rig. I’d much rather stick with a known standard, especially since I’m not an animator and have no experience in retargeting animations from one rig to another.

Here ya go!

Just copy EpicSkeleton_Settings to this directory: MayaTools\General\ART\SkeletonTemplates
and the _Placement to : MayaTools\General\ART\JointMoverTemplates