Animation Changing Maya > Unreal 4.11.2

I’m running into an odd behavior when I import an .fbx into UE4. The animation changes slightly, specifically the feet and hands of the character I’m importing do not remain stationary the way they appear in Maya. I’ve recorded both the animation from Maya and Unreal.

Maya:

95626-uejointshake_001.gif

Unreal 4.11.2:

95627-uejointshake_002.gif

This is only happening to the joints that are being held in place by an IK chain in Maya. My process from Maya is currently to bake all the joint information by single frame intervals, then export the joints (Both the bind and constraint joints) with the mesh, telling it to bake and re-sample all the animation (Again), and save as a binary 2016.1.2 .fbx.

Going into Unreal I’m using these settings to import the .fbx:

I’ve tried this both with the Default Sample Rate and Preserve Local Transformation switched on and off. It also happens no matter which animation compression type I use. I’ve gone so far as to create a blank project and import an .fbx with just the bind skeleton and mesh, and got the same result. When importing the .fbx back into Maya, the joint remains stationary.

Maya is set to 30fps, but I don’t think it’s a sample rate issue, because the frames in which the joints are being moved, are whole frames, and the motion doesn’t seem like a linear interpolation. I can recreate a similar motion in Maya using Evaluation modes (which can cause the constrained joints to move away from each other), but in that case the constraint joint is moving, not the bind, and Maya’s playback modes shouldn’t have an effect on an .fbx that has every frame baked down.

Has anyone run into an issue like this before, or have suggestions as to where Unreal is getting this motion from?

EDIT: After some more digging I discovered that I can recreate the motion in Maya, which means it wasn’t an issue with Unreal, but user error somewhere along the line.

Hi!

Currently UE4 not support FBX 2016.

“…The UE4 FBX import pipeline uses FBX 2014. Using a different version during export may result in incompatibilities…”

Try to export into FBX2015/2014 or FBX2013.

Sometimes the FBX plugin does not correctly recognize complex hierarchy of the rig and bakes the animation with errors. Try to bake animation before exporting. You can use Bake Simulation command in MAYA.

Hey

I did not know that UE4 wasn’t currently supporting 2016, unfortunately neither 2014/2015 or 2013 yielded different results, nor has baking everything before leaving Maya.

I was however able to recreate the motion in Maya. If I export the .fbx from Unreal, import it into Maya, double the length of the animation (adding a frame between every key), and then play it back at 60fps. Even set to linear interpolation, the joints move every frame, and jump back to their original position on every key.

This is making me think they must be inheriting this motion (from where I’m not yet sure), which means it’s not actually an issue with Unreal, but a problem with the rig in that Maya file.

Thanks very much for the help though!