Export animation data into custom curves for Unreal Engine

[Gui]

Hi, I’m trying to create a Facial Animation Sharing system in UE4 - Here.

For unreal to read the animation data, the FBX file need to have specific channels with curve data inside them (not bone translation/rotation, the bone animation data is actually deleted inside unreal)

it would look like something like this inside unreal:

Base asset that connects the curves to bone movement (like FACS system)

Facial animation with custom curve data that drives the base asset

I currently have a mGear character with face controls that drive bones - very similar to the Wayne rig that was shared here - but I have no idea how I need to setup my rig controls in order to be able to export a fbx file with those custom curves like in the picture above!
can someone point me on the right direction? Thanks!

[Pawel_Dziagwa]

Hi
Make attr on root joint with name of curve that you have in unreal.
For example in ue you have jawOpen pose , to drive it you use jawOpen curve. In maya add root.jawOpen attr that will be driven by controlling. Remmember you drive poses. So this attr should be like weight of pose. I hope it helps.

[Gui]

what script commands would you recommend to use to create those custom attr based on the animation data on the controls?

[Milio]

I might be wrong, but by the look of it I’d say these faces are blendshape driven. In order to import easily all the blendshape values you need (as @Pawel_Dziagwa pointed out) to get all that data as a custom attributes in the root of your skeleton. So, every blendshape node you have in your geometry/ies should be added as an attribute on the root, they need be named matching the blendshape node name and connected to it. So when you animate the face, just by using a rig or simply animating the blenshapes sliders, the attribute is taking that (usually 0 to 1) value. Once exported and imported to unreal all those values will be there as custom curves, remember to activate the option.

I’m animating a growing tree…branches and leaves are blenshapes. In the image you can see all the blendshapes i have created added as attributes in the root joint, connected to them and getting the animated value of each blendshape node.

All those are custom curves that are included in the fbx and unreal will show them in the animation editor:

Hope it helps.

Cheers.