Wednesday, May 26, 1999

A Virtual Environment Will Let Brown U. Researchers Walk Through Their Data By LAWRENCE BIEMILLER Providence, R.I. "Cube," says Andrew Forsberg, and a simple cube appears, floating just beyond the reach of two visitors he's brought into a small, bright, line-drawing room at Brown University here. The room has a three-dimensional, line-drawing table, line-drawing chairs, even line-drawing pictures on the walls -- it's a little like standing inside a 1950s cartoon, except that three live humans are there. A simple but computing-intensive trick of stereoscopy gives the images depth, so that you can seem to walk around an object or peer far into the distance. "Sphere," says Mr. Forsberg, speaking into a microphone attached to his shirt. The cube becomes a wire-mesh sphere. "Cone," he says. "Red." The sphere becomes a cone and turns red. Wearing stereo-vision glasses and special touch-sensitive gloves, one of Mr. Forsberg's visitors reaches toward the table, which is set with line-drawing plates and glasses. Mr. Forsberg, a user-interface developer in Brown's computer-science department, explains how to pick up one of the virtual objects: Point at what you want to grasp, then touch a finger to your thumb. As the visitor lifts his hand, the glass rises off the table, rotates, moves toward him -- and then remains floating above the table when he releases the finger from his thumb. Next Mr. Forsberg tells one of the visitors how to change the virtual world's scale: Point at the wall, grasp, and push down. A moment later, three full-size adults are towering awkwardly over a dollhouse room. Such a demonstration may bring to mind Alice's adventures, but the 8-by-8-foot room in which it takes place is actually a wonderland of an altogether different sort -- a high-tech, multi-million-dollar research facility in which state-of-the-art graphics technology runs off of a brand-new supercomputer capable of processing enormous amounts of data quickly. Rick Friedman Andries van Dam in Brown's virtual-reality facility, which he says will let researchers leverage humans' "tremendous capacity for detecting even small visual patterns." The virtual-reality room has three walls and a floor onto which high-resolution images can be projected at up to 30 frames a second, fast enough to seem entirely real. A simple but computing-intensive trick of stereoscopy gives the images depth, so that you can seem to walk around an object or peer far into the distance. A tracking system follows the location of the stereo glasses to keep tabs on where you're looking, and the images are updated as you move your head. To avoid creating distracting shadows, the images are projected onto the three walls from behind. The room's fourth side is open to a larger room that accommodates observers and a bank of computers used to control the virtual-reality cube. The room and the International Business Machines RS/6000 SP next door are the centerpieces of Brown's new $8-million Technology Center for Advanced Scientific Computing and Visualization, which opened formally Wednesday afternoon. The center is intended, in part, to let researchers from departments across the campus visualize and even hear their information by literally immersing themselves in it. For instance, physicists will be able to stand in the middle of a three-dimensional, audio-enhanced flow of information from a large data set -- an abstract representation that can be changed on the fly to highlight any passing phenomenon that seems interesting. Planetary geologists will be able to wander through a realistic Martian landscape re-created from satellite images. "This lets them be in the field," says Mr. Forsberg. The center will also give computer scientists here an opportunity to explore new ways in which people and computers can interact. The planetary geologists, for instance, might be able to change the way data are displayed in the virtual room simply by giving a voice command, or by grasping a virtual Martian peak and stretching it -- much easier than lugging a keyboard and a mouse around the surface of Mars. "We're trying to get as natural a dialogue going with the computer as we can," says Andries van Dam, a professor of computer science who helped lead the effort to get the new facility built. He also says the facility will pair "the best of parallel computing and the best of pattern recognition, which is what we have in our heads -- wetware." Mr. van Dam points out that a large proportion of neurons in the human brain are devoted to vision -- many more than to the other senses. Humans, he says, also have "a tremendous capacity for detecting even small visual patterns." "That's what we're leveraging when a scientist tries to visualize data," he says. The high-powered supercomputer is necessary, Mr. van Dam says, for working with computer models and data sets that offer a great deal of spatial or temporal detail. "To simulate a process, you might want to look at it over very fine steps of time," he says. The RS/6000 SP has 100 C.P.U.'s, or central processing units -- "many hands make light work," as Mr. van Dam puts it. The supercomputer's speed is also necessary to keep up with the brain's. Mr. van Dam says images in the virtual-reality cube must be updated quickly to avoid "simulator sickness," a dizzying condition that develops if the body feels it's doing one thing while the eyes are seeing something different. Even the sound system will reinforce scholars' ability to see their information, says George Boes, computing director for Brown's fluid-mathematics center. "If you were looking at turbulent flows, you could assign a sound to represent a new turbulence that would be outside your cone of vision -- an audio clue," he says. Brown's new center, the latest in a series of virtual environments on university campuses and elsewhere, is the result of a close collaboration between the university and I.B.M. It grew out of 1997 National Science Foundation grant for major-instrument research. It is not the most elaborate virtual-reality facility -- a few six-sided rooms have been constructed elsewhere, although they're considerably more expensive. Virtual-reality rooms are often known as "caves," although the acronym CAVE -- for Cave Automatic Virtual Environment -- belongs to a specific technology created at the Electronic Visualization Laboratory at the University of Illinois at Chicago. Although he is clearly a fan, Mr. van Dam says virtual-reality technology has yet to prove itself invaluable, at least as far as scholarly research is concerned. "There are dozens of CAVEs out there, but no real hard scientific evidence that they help you do your science better," he says. One project Brown computer scientists have in the works, he says, will involve running controlled studies to see whether the facilities really enhance scholarship. Samuel Fulcomer, the Brown center's director, notes that the facility here is unique in at least one way: It runs on I.B.M. hardware, while other virtual-reality facilities use computers from SGI, formerly Silicon Graphics. Some of the equipment I.B.M. is providing through a research-partners program, some it is giving to Brown directly, and some Brown is buying. For Brown researchers, the I.B.M. equipment is something of a drawback -- they'll have to create all their virtual-reality software more or less from scratch, rather than taking advantage of existing programs that run only on SGI machines. As of now, the center has a handful of fairly basic demonstration programs, some borrowed and some homemade, that Mr. Fulcomer says don't show off "the performance we expect to get out of the parallel hardware." The benefit to collaborating with I.B.M., however, is that the company is working closely with computer scientists here to assure that they have the equipment they need. For instance, company technicians are building a device that will allow each wall of the cube to be powered by four computers, instead of one. With four machines, each processing a quarter of the image, the virtual environment will be capable of handling more-detailed information -- with the detail represented by either a greater resolution in the images or smaller amounts of time between the events' being displayed, or both. Mr. Fulcomer says the center will also serve Brown researchers who want to take advantage of the new computer's capacity, but don't need to see their data in three dimensions. The new machine is five to six times as powerful as the next-most-powerful computer on the campus, he says -- and something like 100 times as powerful as the average P.C. Such capacity is necessary, he says, because some researchers who use the center work with data sets that would fill the hard drives of 50 desktop machines -- and, he says, such a data set "could just be a short time sequence," a small portion of a larger event that a researcher is studying. Some data sets are so large that they can't be moved over the campus computing network. Instead, they're brought to the new facility on magnetic tape. To help manage such quantities of information, Mr. van Dam says, computer scientists here will also be studying new programming techniques that would let researchers alter computations once they're under way. "As a computer is working, a scientist could say, `Wait, give me more of this.' You could steer the computation," he says. The techniques, which he says could take "quite a while" to develop, would give researchers "a new way of doing horrendously large computations," he adds. Computations that large are common in weather research, drug design, physics, and other areas. Mr. Fulcomer notes that more and more corporations are also using virtual-reality facilities for product design and testing. And the facilities would be "a natural" for architects, who could let clients see three-dimensional representations of proposed buildings. Don't expect to see your kitchen renovation in a virtual environment next week, however -- the computing power behind immersive virtual reality is still wildly expensive. Mr. Fulcomer says that, as configured, the I.B.M. RS/6000 SP that powers the environment here is probably worth $7-million. Mr. van Dam says it's only a matter of time before virtual reality becomes commonplace. "This CAVE is exotic, one of only 30 or 40 in the world," he says. "But Moore's Law is that every 18 months, compute power doubles. It will be much less exotic in five years." For the time being, however, virtual reality is exotic indeed. Mr. Forsberg's tour of the line-drawing room takes a turn toward the dreamlike when the visitor who has reduced the virtual world to dollhouse size tries to make it bigger. Alice-like, he goes too far, expanding the world until it is much larger than the people in it. Several attempts to rectify matters only make them worse. Mr. Forsberg and his guests end up floating above the table. It's only a demo, after all. Even so, it's briefly disconcerting when Mr. Forsberg says -- speaking directly to his guests now, rather than into the microphone -- "There's no reset." Background story from The Chronicle: A Key for Entering Virtual Worlds (11/16/94)