The MiniCAVE - A Voice-Controlled IPT Environment

摘要

The computer hardware for the CAVE and similar immersive projectiontechnologyrn(IPT) virtual reality (VR) environments are normally high-end SiliconrnGraphics systems with expensive CRT-based projection systems. The idea behind thernMiniCAVE concept is to downscale the computing hardware to fast PCs runningrnWindows NT and to downscale the projection systems to relatively inexpensive andrnrelatively robust LCD projection systems.rnMuch to our surprise, when we started this project in early 1998, the performancernof a 200 megahertz Pentium Pro (at $3,000) was competitive with the performance of anrnSGI Onyx RE2 (at $120,000) when running matrix-oriented mathematics software. Thisrnsuggested that a much cheaper version of the CAVE might be assembled using Pentium IIrnhardware. Currently, we are working with a PC that has two 466 megahertz processors.rnAlso, both resolution and frame rates of LCD-type projectors have improved substantiallyrnduring the last few years. Brightness already is substantially better than CRT systems.rnThis makes the development of an IPT environment, the MiniCAVE, based on PCrntechnology and LCD-type projectors feasible. The MiniCAVE should cost less thanrn$100,000 after development.rnAnother problem that typically occurs with full scale CAVE environments is thernlarge amount of space; often 12x12x12 foot plus extra space for the rear projection. Wernpropose a 6x6x6 foot MiniCAVE. The reduction in dimension allows that this IPTrnenvironment can be placed in many regularly sized rooms available at universities andrncompanies. Also, the halving of the linear dimension of the projection walls matches thernresolution capabilities of LCD projectors.rnAs a first software example (and just using one PC), we have successfully ported arnstereoscopic fly-through demonstration package from SGI Unix using GL to WindowsrnNT using OpenGL. Windows NT supports the CrystalEyes liquid crystal shutter glassesrnso that stereoscopic displays are available in a PC environment. While most PCrnapplications use the desktop metaphor for navigation, moving to a virtual realityrnenvironment suggests another metaphor that is more appropriate. We have implemented a voice-command interface for the Windows NT environment so that the user can controlrnfeatures of our stereoscopic fly-through demonstration by simply using voice commands.