Tracking

See also: Positional tracking

Tracking allows the VR or AR system to know where your head (HMD), hands and other body parts (Input Devices) are looking and moving. Tracking is important to accurately render the virtual world to match your physical positions and movements.

Tracking can either be 3DOF (rotation only) or 6DOF (position and rotation). Early VR tracking technology in the 1990s used magnetic tracking systems that used either AC magnetics or DC magnetics depending on the provider.

The Magic Leap 1 uses 6DOF magnetic tracking for its controller, but it is poor quality.

Rotational Tracking

Rotational tracking tracks an object's movement in all 3 rotational directions: pitch, yaw, and roll. Rotational tracking is usually performed by IMUs such as accelerometers, gyroscopes and magnetometers.

Positional Tracking

Positional tracking tracks an object's movement in all 3 translational directions: forward/back, up/down, left/right. Positional tracking is usually more difficult than rotational tracking and is accomplished through different Types and Systems.

Tracking Systems

Lighthouse - laser-based system developed by Valve for SteamVR.

Constellation - optical-based system developed by Oculus VR for Oculus Rift (Platform).

WorldSense - developed by Google that uses markerless inside-out tracking.

Comparison of tracking systems

See also: Comparison of tracking systems

There are several consumer-level tracking systems currently available. Originally, these were used for interaction with regular non-VR video games, but more recent tracking systems have been used for VR systems.

Brand & Model	Tracking system	Inside-out	Outside-in	Marker-based	Marker light frequency	IMU	Spacial resolution (mm)	Latency (ms)
Facebook/Oculus Rift	Constellation	No	Yes	Yes	Infrared	Yes	?	?
IndoTraq	HSVT	Yes	No	No	Infrared	Yes	0.3	10
HTC Vive/SteamVR	Lighthouse	Yes	No	Yes	Infrared	Yes	0.3	15
Microsoft HoloLens	??	Yes	No	No	Infrared	Yes	?	?
Nintendo Wii Remote	??	Yes	No	Yes	Infrared	Yes	?	?
Sony PSVR	??	No	Yes	Yes	Red/Green/Blue	Yes	?	18
Google	WorldSense	Yes	No	No	?	Yes	?	?