VALERIE Lehner and I stood in the cab of a Caterpillar Inc. front-end loader as it circled the floor of an Arizona rock quarry, scooped up a bucket full of stones, turned and dumped them.
But we weren't really standing in the cab. And we weren't really in Arizona. And Lehner didn't really dump the stones, even though it looked and sounded like stones dumping right in front of us.
That's because we were standing in what Lehner and other researchers call "the CAVE."
The CAVE is a small room at the National Center for Supercomputing Applications on the Urbana campus of the University of Illinois. The supercomputing center is a mecca for applying virtual reality technology to science and engineering problems.
CAVE is an acronym for Cave Automatic Virtual Environment. It's also a reference to "The Simile of the Cave," a discussion of perception, reality and illusion by the ancient Greek philosopher Plato in "Republic."
A person standing in the Urbana CAVE and wearing a pair of stereoscopic glasses enters a three-dimensional world of sights and sounds created by computers.
This technology is similar to virtual reality games found today in some video arcades, except for two things: its use and sophistication. The CAVE is used for serious scientific research. Sophistication? Virtual reality games are to the CAVE what Flash Gordon's spaceship is to the Starship Enterprise.
"Sure it's `gee whiz' and `cool,' " said Kem Ahlers, a researcher with Peoria-based Caterpillar. "But that's not why we're here. It's a new technology we can use to make better products for our customers."
Lehner, Ahlers and other researchers have designed and built a prototype of a front-end loader on a computer, then translated it into a virtual front-end loader for display in the CAVE. In essence, the CAVE has become their new test track.
The Caterpillar work may be the best example of using the CAVE for applied science. But the CAVE has attracted researchers from around the country who use it for basic scientific research, too. They study such things as colliding galaxies, developing chicken embryos, brewing thunderstorms and the changing shapes of surfaces sculpted by mathematical equations. "We've got lots of ideas about where we'd like to take this," Ahlers said. "The technology is only just past its infancy." A New Visual World
Using supercomputers as tools, the researchers "build" their objects of study in computer simulations, be they molecules, thunderstorms or star clusters. The simulations get translated into realistic color images that change over time. In such a way, for example, they can "visualize" how a simple cloud grows into a dangerous thunderhead.
Computer visualization of scientific phenomena has grown dramatically over the past decade, powered largely by developments at the Illinois center and other supercomputing labs established by the National Science Foundation. The coins of the realm for this trend are moving images displayed on computer screens and videotape.
The CAVE represents an evolutionary step into three dimensions.
"The CAVE - and virtual reality in general - is the first new paradigm in 3-D image representation since the Renaissance, when perspective was developed," said Thomas DeFanti, a co-inventor of the CAVE who's based at the U of I's Chicago campus.
By displaying their simulations in the CAVE, researchers examine their data by literally walking around and through it. This allows them to use the most sophisticated computer ever developed for analyzing visual data in three dimensions - the human eye-brain system.
That's important because these scientists work with a tremendous amount of data. And the best way to find crucial patterns in that data is to look at it.
Most researchers are "amazed" at the feeling of immersion they get in the CAVE, …