tracking

In 3D human-computer interaction, 3D tracking, also called pose tracking or positional tracking, is a process that tracks the position and/or orientation of head-mounted displays, controllers, or other input devices within Euclidean space. Pose tracking is often referred to as 6DOF tracking, for the six degrees of freedom in which the objects are often tracked.
In some consumer GPS systems, orientation data is added additionally using magnetometers, which give partial orientation information, but not the full orientation that pose tracking provides.
In virtual reality (VR), it is paramount that pose tracking is both accurate and precise so as not to break the illusion of a being in virtual world. Several methods of tracking the position and orientation (pitch, yaw and roll) of a display and any associated objects or devices have been developed to achieve this. Many methods utilize sensors which repeatedly record signals from transmitters on or near the tracked object(s), and then send that data to the computer in order to maintain an approximation of their physical locations. A popular tracking method is Lighthouse tracking. By and large, these physical locations are identified and defined using one or more of three coordinate systems: the Cartesian rectilinear system, the spherical polar system, and the cylindrical system. Many interfaces have also been designed to monitor and control one's movement within and interaction with the virtual 3D space; such interfaces must work closely with positional tracking systems to provide a seamless user experience.
Another type of pose tracking used more often in newer systems is referred to as inside-out tracking, including simultaneous localization and mapping (SLAM) or visual-inertial odometry (VIO). An example of a device that uses inside-out positional tracking is the Oculus Quest 2.

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