centerNode
The center of the face, defined to have the origin located behind the nose and between the two cheek bones.
Z+ is forward out of the nose, Y+ is upwards, and X+ is towards the left. The units are in meters. When the face trackable state is TRACKING, this pose is synced with the latest frame. When face trackable state is PAUSED, an identity pose will be returned.
Use regionNodes to retrieve poses of specific regions of the face.