Getting animated custom attributes into Unreal animations from Maya.

Currently, I have a blendshape based rig in Maya that I am using to export to FBX and import meshes, skeletons and animations into Unreal. This is working fine.

What I want to do with it now, though, is add extra animation curves for attributes related to materials. According to the documentation, and what I can find on forum posts, what I need to do is create “custom attributes” in Maya, set animation keys for them, then in the FBX Importer options, ensure that “Import Custom Attribute” is checked (and probably also “Set Material Curve Type”, though if I understand correctly, I could just set these values to be material curves in the asset editor when it’s imported).

I have been able to add example new values via the Attribute Editor in various places, and set keys on these by importing values from an ATOM file. I can see that they update in the channel box, when moving through frames, in the same way that I can see the influences of blend shapes change. The attributes I have been naming “MaterialOne”, “MaterialTwo” and “MaterialThree”, they are of type float and set to be keyable.

However, when I export to FBX and import into Unreal, I only see animation curves for the blend shapes and not my custom attributes. Maya FBX export documentation suggests that custom attributes will only be exported when applied to transform of Material nodes - I wondered if that was the issue? But setting my blendshape rig mesh to a new Blinn material and adding animated attributes to that had no effect, regardless of whether I opted to import materials from the FBX or not.

I’m afraid I am a software engineer rather than a digital artist, and I have little knowledge or experience of Maya, so I’m stumped as to what I need to do to create these material curves.

Can anyone help?

I have finally got this to work by creating the attributes in a Joint node for the skeleton that is exported along with my blendshape rig.

1 Like