Mixamo Animation Retargeting plugin is participating to the Unreal Engine Massive Marketplace Sale and is 30% OFF right now. If interested, get it before the end of event.
Hi! Here the new video tutorial on how to create standard Root Motion animations from Mixamo animations. The process is very simply (few clicks!) and requires both the “Normal” and the “In-Place” versions of the Mixamo animation you want to convert.
Hi! As we continue creating new versions of the old videos, here is the new “Animation Tuning” video.
When using the UE4 Retargeting System is common to have some defects in the end results. This is caused by the different morphologies of the involved skeletal meshes, that are not taken into account by the UE4 Retargeting System.
In the video is explained the general problem, and two possible solutions are provided. Both of them are very easy and can be done in few minutes directly inside the UE Editor.
Assertion failed: (Index >= 0) & (Index < ArrayNum) [File:D:\RocketSync\4.26.0-14830424+++UE4+Release-4.26\Working\Engine\Source\Runtime\Core\Public\Containers/Array.h] [Line: 674] Array index out of bounds: 1 from an array of size 1
Hey, loving the plugin! I’m really confused as to why I keep getting this crash when trying to generate root motion animations. The skeleton has not been edited at all from the default mixamo rig apart from the root bone being added by the plugin. Any thoughts on this?
About the error, looking at the plugin source code, the issue is that your “in-place” Mixamo animation has fewer key-frames than the corresponding “normal” Mixamo animation. Correct animation pairs are expected to have the exact same number of key-frames.
If the problem persists, please share the original FBX files of the Mixamo character and the two Mixamo animations: send a download link at support@.com . So we can investigate precisely the issue.
Hi! Here the last new video, that explains how to workaround the “FBX Import Error” message that can be raised by UE4 when trying to import a new Mixamo animation using an already retargeted skeleton:
This is a known behavior/limitation of the UE4 Editor: when importing an animation, the import fails if the bones hierarchy is not equal to the one of the specified skeleton. When the plugin is applied to a Mixamo skeleton, it modifies the skeleton and all the connected animations and skeletal meshes stored in the project, adding the root bone to them. This causes this sort of issue. Look at the tutorial to discover how to solve it!
I am attempting to use this plug-in. It sort of works. However, the root bone it adds only goes about 2/3 of the way to the floor. This means all the animations sway and have large foot slips. This video shows an animation on the Mixamo skeleton and you can see the short root bone:
This video shows the animation on the UE4 skeleton and you can see the standard long root bone:
The root bone is always placed at (0, 0, 0) by the plugin, that is the correct position expected by UE4.
I suspect your imported character has a wrong vertical offset (Z axis).
You could try to verify it looking at your original FBX file (e.g. in Blender) and checking the coordinates of the foots (they should be at 0).
(never tested it, but it could help) In UE4, using the original FBX model, you could try to disable the “Auto Align Floor to Mesh” option in the Scene Setup settings:
If the character is properly positioned, it should stay perfectly on top of the rendered floor.
Thank you. This morning I tried many, many characters from Mixamo finding the root bone was always wrong, until I stumbled across the character Exo Gray. It works perfectly now! So, for anyone else just trying to download animations, there’s a character you can use to get good results. This plug in is awesome and now I have access to the animations on Mixamo for my next game.
EDIT: Just going to chalk this up to using UE5 which is unsupported, my apologies.
After retargeting my mixamo skeleton, any mixamo imported animation breaks immediately.
I’m unsure how to fix this, I’ve made sure that my rig is set to Humanoid and even resorted to using the swat character shown in the example to ensure it’s not a model issue.
Has anyone else dealt with this and is there way to fix this?
We not tested it with UE5, but I think the simplest solution is to use the plugin with UE4.26 to retarget the needed animations and skeletons, then migrate all the processed assets to your UE5 project.
Just bought this and am reading through this thread and the tutorials etc and wondering how I’ve never discovered it before.
I’ve had so many problems in the past having to mess around trying to fix Mixamo animation in Blender and wanting to bang my head off the desk because there was always something that cause issues - so I’m really hoping that this plugin makes things as easy as it sounds.
Excited to get some free time and try it out, will update this post when I have!
