Other Body Movements
Foot position, head position (with a 3-D tracker), and even the direction of gaze of the eyes [1, 5] are also usable as computer inputs.

Virtual Reality Inputs
Virtual reality systems rely combinations of the 3-D devices discussed above, typically amagnetic tracker to sense head position and orientation to determine the position of the virtual camera for scene rendering plus a glove or other 3-D hand input device to allow the user to reach into the displayed environment and interact with it.