Get Tracking Reference Component
Enables your application to add an object which the camera will follow, if you don’t want the camera to follow the first PlayerController (which is the default, and is the approach used by most applications).
Get Tracking Reference Component retrieves a reference to a tracking reference component. This component is an optional VROrigin object for the in-game MR capture camera to follow. It acts as the origin of the tracking space. If object is not set, the camera will follow the first PlayerController as the tracking reference.

- A reference to an optional VROrigin object.