What Is Virtual Reality?

3. Types of VR Systems

  A major distinction of VR systems is the mode with which they interface to the user. This section describes some of the common modes used in VR systems.

3.1. Window on World Systems (WoW)

  Some systems use a conventional computer monitor to display the visual world. This sometimes called Desktop VR or a Window on a World (WoW).   This concept traces its lineage back through the entire history of computer graphics. In 1965, Ivan Sutherland laid out a research program for computer graphics in a paper called "The Ultimate Display" that has driven the field for the past nearly thirty years.

  "One must look at a display screen," he said, "as a window through which one beholds a virtual world. The challenge to computer graphics is to make the picture in the window look real, sound real and the objects act real." [quoted from Computer Graphics V26#3]

3.2. Video Mapping

  A variation of the WoW approach merges a video input of the user's silhouette with a 2D computer graphic. The user watches a monitor that shows his body's interaction with the world. Myron Kruger has been a champion of this form of VR since the late 60's. He has published two books on the subject: "Artificial Reality" and "Artificial Reality II". At least one commercial system uses this approach, the Mandala system. This system is based on a Commodore Amiga with some added hardware and software. A version of the Mandala is used by the cable TV channel Nickelodeon for a game show (Nick Arcade) to put the contestants into what appears to be a large video game.

3.3. Immersive Systems

  The ultimate VR systems completely immerse the user's personal viewpoint inside the virtual world. These "immersive" VR systems are often equipped with a Head Mounted Display (HMD). This is a helmet or a face mask that holds the visual and auditory displays. The helmet may be free ranging, tethered, or it might be attached to some sort of a boom armature.

  A nice...