Tracking

Overview

Introduction to Tracking

Positional tracking detects the precise position of the head-mounted displays, controllers, other objects, or body parts within Euclidean space. Because the purpose of VR is to emulate perceptions of reality, it is paramount that positional tracking is both accurate and precise so as not to break the illusion of three-dimensional space. Several methods of tracking the position and orientation (pitch, yaw, and roll) of the display and any associated objects or devices have been developed to achieve this. All said methods utilize sensors that 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. 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.

Types

3DoF

Three Degrees of Freedom, or 3DoF, is a virtual reality concept that describes how learners interact with a virtual environment. With 3DoF, learners can:

• Look left and right

• Look up and down

• Pivot left and right

3DoF means learners cannot move throughout the virtual space. However, learners can interact with the environment via gaze control or a laser pointer controller. 3DoF can be useful for practising job duties that are significant yet sedentary, like navigating difficult conversations with coworkers.

6DoF

In AR and VR, 6DoF describes the range of motion that a head-mounted display allows the user to move on an axis in relation to virtual content in a scene. Three of the degrees refer to the motion of the user's head - left and right (yaw), backward and forwards (pitch), and circular (roll) - while the remaining three pertain to the movement within the space - left and right, backward and forwards, and up and down.