Streaming custom attributes from Maya to Unreal

When live linking a skeleton joint from Maya to Unreal, you can choose to stream any keyframed custom attributes. This is useful for enabling compound or custom behavior.

Streaming custom attributes to a character

To stream custom attributes to a character:

1. In Maya, create a custom float attribute on a joint and make sure to set at least one keyframe on it.

2. Export the joint (or entire skeleton) as an FBX file.

3. Import the file into Unreal, making sure to enable the following.

   • Import Animations
   • Import Custom Attribute
   • (Optional) Do not import curves with only 0 values

Now if you open Unreal's Asset Editor, you'll see the custom attributes on the skeleton. You can then alter the values in Maya to stream them to Unreal.

Streaming custom attributes to a camera / light / prop

If you intend to stream a custom attribute to a camera, light or prop, you must do so through an Unreal level sequence.

To stream custom attributes to a camera, light, or prop:

1. In Maya, create a custom float attribute on a camera, light, or prop and make sure to set at least one keyframe on it.

2. In Unreal, create a blueprint for the object.

3. Add a variable to the blueprint with the same name as the custom attribute in Maya (make sure to use the long name, not the equivalent nice name), and enable the following options on it:

   • Expose to cinematics
   • Instance Editable

4. Compile and save the blueprint.

5. In Maya, add the object to the Unreal Live Link Editor and click the link button next to it.

6. In the Asset Selection window, create a new actor by typing a name into the actor textfield, then set the Type to the new blueprint you created. Click Create.

7. Create a new Level Sequence, then click Link.

The custom attributes are now linked between Maya and Unreal.