How does VR Preview relate to PlayerController/CameraManager?

When VR Preview is run, how is the HMD (in this case DK2) set up in regards to the camera in the pawn? I’m mainly interested in figuring out where does the tracking camera origin get placed (is it a default distance in front?) I’m guessing the tracking camera is set to a default position in front of the unreal camera that is in the pawn and the positional tracking is applied on top.

On a technical note, what is the organisation between the HMD, PlayerController and CameraManager?