bidirectional interaction between humans and computers

A necessary but not sufficient characteristic of Virtual Reality (VR) is causal-chain communication between someone and their computer. Communication from a person to a computer may have computer monitoring of finger, hand, head, eye and/or body movement and/or speech interpretation. Information transfer from a computer to a person may have three-dimensional image renderings, audio production, and kinesthetic (touch and motion) simulation. VRMLmagic has further information on this topic that may be of interest.

Eventually, computing systems might be able to model a virtual three-dimensional model of the human body in real time by combing images from several video cameras in like manner to how one's brain put togethers pictures from two eyes. In any event, human perception is neither low-level nor easy to duplicate. While humans have adapted to deal with things that leave the direct line of vision, are in the dark, or are complex, such conditions challenge optical tracking by current computing systems. With future formation, computers may be better able to create 3D models from optical pictures, opening the door for more precise optical monitoring of human movement. Link to Virtual Tours Irvine, California may also prove interesting.

As a source for additional material, see Holographic Virtual Reality .