disable positional tracking, how?

I have a mode in my scene where i need to disable positional tracking but continue to have rotational motion tracking. (Its inside a photosphere so the user needs to stay centered). That was easy with the OVR package, is there a way with the integrated UnityEngine.VR?

 

Make a script on the parent object of the camera that moves the transform position to counteract the position on the camera transform. It should do it