Virtual Reality - Virtually
Here(Note that due to space limitations this section was not published with the story.)
Several technologies we examined either fell somewhere short of our criterion for VR or vastly exceeded it. We cover them here as they complete the spectrum, the bigger picture in which VR fits. Virtual VR, the low end of the spectrum, can be a useful introduction to VR for some. Super VR is where PC-based VR is headed.
Animation programs can produce Virtual VR - via pre-rendered movement through a virtual world. Traditional 3D animation programs such as 3D Studio generate .flc, .fli, and .avi files that can be used to create pre-rendered fly-throughs but lack any freedom of movement in real time. Of particular note here is Virtual Reality Labs' Vista Pro, an inexpensive, easy to use program in which you can design terrains with trees, foliage, water and more, then render a fly-through. Later this year HSC Software's Bryce will come to Windows with animation capabilities, allowing you to easily create worlds of incredible beauty on the PC and save them as fly-throughs. Such programs currently provide levels of detail and complexity beyond what can be rendered in real time in VR today - but not for long!
Moving up a notch we find Apple's QuickTime VR and Warp's VTV (Virtual TV). Consider an image wrapped on the inner surface of a cylinder or sphere. Now imagine looking through a camera while standing at the center of the cylinder or sphere. Though you see only a small portion of the scene at a time you are free to look up, down, and around. You can even zoom your camera in and out. But you can't move around. Warp promises this same viewing technique for video, using a sphere - as the video proceeds you get to look around and zoom in and out, similar in effect to viewing an Omnimax film projected onto a huge dome.
VirtualVR also includes immersive but passive forms of entertainment. These include Disney's Star Tours ride as well as Universal Studio's Back to the Future ride, both of which place you in a physical vehicle on a motion platform, a trick learned from military flight simulators, arguably the birthplace of virtual reality.
Today's simulators, used by both the military and commercial aviation for training provide the most compelling illusion of reality, commonly raising their user's blood pressure and pulse. These devices, though able to induce a sweat, are not the ultimate in VR. To provide the absolute real time performance their simulated missions require they must flatten or pre-compile the visual database, placing serious constraints on what can and cannot be altered during a simulation. You can't just land anywhere, get out, and walk around - all you can do is fly.
Not so constrained is the CAVE, or Cave Automatic Virtual Environment, a technology developed at the University of Illinois in Chicago. Several CAVE dwellers, donning Stereographic's CrystalEyes, may enter at once, surrounded on 3 sides and below with a virtual world that extends to within inches of your face and responds in real time - thanks to the processing power of Silicon Graphics Onyx computers with Reality Engine graphics acceleration. The CAVE is the closest we have seen to Star Trek's Holodeck on the Enterprise. The downside? For now a CAVE costs about $1 million and $30 thousand just to transport and set up. But reality is getting cheaper. The new Sapphire pci accelerator from Future Vision Technology can be installed 2 or 3 to a system. So equipped, a multiprocessor PC can drive the 3 stereo-ready projectors that create the CAVE experience.
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Updated Jan 28, 1998