fighter aircraft, it's been found necessary to forbid simulator users to fly or drive for a period of time after flying the simulator"). Levels of VR Hardware SystemsThe following defines a number of levels of VR hardware systems. These are not hard levels, especially towards the more advanced systems. Entry VR (EVR)The 'Entry Level' VR system takes a stock personal computer or workstation and implements a WoW system. The system may be based on an IBM clone (MS-DOS/Windows) machine, an Apple Macintosh, or perhaps a Commodore Amiga. The DOS type machines (IBM PC clones) are the most prevalent. There are Mac based systems, but few very fast rendering ones. Whatever the base computer it includes a graphic display, a 2D input device like a mouse, trackball or joystick, the keyboard, hard disk & memory. Basic VR (BVR)The next step up from an EVR system adds some basic interaction and display enhancements. Such enhancements would include a stereographic viewer (LCD Shutter glasses) and an input/control device such as the Mattel PowerGlove and/or a multidimensional (3D or 6D) mouse or joystick. Advanced VR (AVR)The next step up the VR technology ladder is to add a rendering accelerator and/or frame buffer and possibly other parallel processors for input handling, etc. The simplest enhancement in this area is a faster display card. For the PC class machines, there are a number of new fast VGA and SVGA accelerator cards. These can make a dramatic improvement in the rendering performance of a desktop VR system. Other more sophisticated image processors based on the Texas Instruments TI34020 or Intel i860 processor can make improvements that are even more dramatic in rendering capabilities. The i860 in particular is in many of the high-end professional systems. The Silicon Graphics Reality Engine uses a number of i860 processors in addition to the usual SGI workstation hardware to achieve stunning levels of realism in real time animation. An AVR s...
