Chapter 4 – Locomotion Interfaces

Publisher Summary Locomotion is a special type of movement. Locomotion, as used by life scientists, refers to the act of an organism moving itself from one place to another. This includes actions such as flying, swimming, and slithering. For humans, locomotion is walking, running, crawling, jumping, swimming, and so on. One way to think of these interfaces is that they are virtual-locomotion interfaces for virtual scenes. Many common virtual-locomotion interfaces take input from only the user's hands; for instance, three-dimensional (3D) computer video games are operated by joystick, keyboard, mouse, and/or game controller. In the real world, Segway PTs, hang gliders, and skateboards require users to lean and shift their weight to control motion. In a virtual reality system that has a real-walking locomotion interface, people use their bodies in a completely natural fashion to walk about the virtual scene. Even though both arms and both legs may be involved in controlling a vehicle and the whole body may be involved in receiving feedback about the state of the vehicle, simulating movement resulting from operating a vehicle is conceptually different from simulating the movement of a human walking about human-scale spaces such as buildings and ships. In a vehicle, users' intentions of direction and speed are specified unambiguously by their interaction with the controls of the vehicle. The challenge for virtual-locomotion interfaces is to capture the user's intent using data that can be derived from sensing the pose (position and orientation) and movement of the user's body.