I tried to switch out Ethan in the Humanoid Animation Recorder sample with a custom Avatar. I followed the directions in the manual to the best of my knowledge. This is the error it gives me.
NullReferenceException: Object reference not set to an instance of an object
AnimatorAvatar.Start () (at Assets/NuitrackSDK/Tutorials/Motion Capture/FinalAssets/Scripts/AnimatorAvatar.cs:18)
Make sure that the character animator is set in the AnimatorAvatar component in the animator. You should also check the model settings: Rig should be configured for Humanoid.
Also check that all bones that you want to use in the AnimatorAvatar component are configured in the humanoid
Check the values passed to GenericRecorder(Transform[] recordableTransform, Transform rootTransform) for recordableTransform and rootTransform: they should be non-null.