Guillaume Laferriere

The APEX abstract controls aren't currently supported in H21. It's a known limitation, but your post reminded us to make sure the Metahuman human face rig works in the Motion Mixer in the next Houdini version.

Give it a try with this scene.

You need to access the control_data output of the rig in order to extract the animated transform values.
I'm using a wrangle to get the xform output values of each TransformObject from the @parms dict detail attribute and stamp it to each point transform. If you inspect the geometry spreadsheet of the invoke_get_animated_control_parms node, you'll also notice you have access to the other output port values of the TransformObject nodes.

Look for hou.ChannelList.addGeometryChannels() in the hom documentation. It allows you to put the channel in the animation editor.
You’ll also need to call hou.playbar.setChannelList().