Through the 3-D Looking Glass

By Philip Elmer-DeWitt

On one screen, a swirling storm cloud slowly twists itself into the characteristic funnel shape of a killer tornado. On another, molecules the size of baseballs jostle frantically for position, each seeking out a comfortable docking site on another's surface. On a third screen, a small child in bright white diapers rises on stubby legs and toddles across a room.

These remarkable moving images and hundreds like them on display last week in Philadelphia at the tenth annual exposition of the National Computer Graphics Association are more than pretty pictures. Each represents a three- dimensional microcosm, stored within the memory of a computer, that human operators can turn, twist and reshape all they want. When special goggles, bodysuits and gloves are used to display and manipulate the images, those microcosms can become so real that viewers feel they have stepped through a kind of electronic looking glass into a completely artificial, computer- generated world.

Three-dimensional computer graphics, the technique by which digital machines generate realistic-looking objects and move them as fast as they would move in real life, has come of age. Architects are using 3-D technology to let clients walk through buildings before they are constructed. Scientists employ it to visualize phenomena too fast, too small or too explosive to be seen firsthand. Industry is relying on it to speed up design and production cycles.

As 27,000 artists, engineers and enthusiasts gathered for their big show, the computer-graphics experts had special reason to celebrate. Late last month two of their own, John Lasseter and William Reeves of Pixar, a computer manufacturer in San Rafael, Calif., won the first Academy Award given for a totally computer-generated film -- a short subject called Tin Toy that starred a rambunctious baby and a windup music man. Says Jaron Lanier, founder of VPL Research, a small Redwood City, Calif., company that makes the equipment used to help people enter a computer-generated world: "This is the year that this stuff is finally starting to work."

Behind the burst of activity is a dramatic advance in computer technology. Over the years, computer scientists have devised an impressive array of mathematical techniques, or algorithms, for rendering 3-D images on a 2-D computer screen. Traditionally, these algorithms -- for drawing things in perspective, for example, removing surfaces hidden from the viewer's line of sight or painting finished objects with texture and shade -- have been encoded in programs and stored in computers as software. As such, they used up massive quantities of computer time. To draw a simple object ten times a second, the minimum needed to create the illusion of motion, took 1 billion calculations a second. The highly polished images that won Tin Toy its Oscar took some 12 trillion calculations each.

But in the past five years much of this mathematical logic has been incorporated into tiny, special-purpose computer chips. Graphics calculations that used to require a $250,000 bank of hardware can now be performed by a single plug-in board. In just the past year the cost of an entry-level 3-D computer has fallen by nearly 70%, to less than $16,000. Within the next five to eight years, predicts Jim Clark, chairman of Silicon Graphics, the leading manufacturer of 3-D workstations, "we'll see the kind of images Tin Toy represents on an ordinary personal computer."

These advanced machines have already started to change the way Americans work and play. The packaging for dozens of name-brand consumer products, from Ivory Snow to Kleenex tissues, is now designed on 3-D computers rather than from mock-ups made of cardboard or clay. Last year the entire line of Coca- Cola soft drinks was redesigned around a new logo -- a project that would have taken twice as long had it not been done by machine. Timex wristwatches, Ping golf clubs, Reebok sneakers and Volvo station wagons are all created on graphics workstations. Volvo even uses a satellite hookup to connect its design computers in California with its manufacturing computers in Gothenburg, Sweden. If a new model does not leave sufficient headroom to accommodate the average American driver, the computer in Gothenburg can spot the oversight before the car gets built.

Scientists are also reaping rewards from 3-D visualization. By studying insulin molecules modeled on a computer, the Danish biotechnology firm Novo- Nordisk was able to create a synthetic insulin that did not clump when injected into the blood, an insight that cut three years off the usual eight- year research-and-development cycle for a new drug. By displaying weather data on a computer, researchers at the University of Illinois have been able to capture the exact moment when a tornado forms within a thunderstorm, a breakthrough that if incorporated into an early-warning system, could one day save lives.

Some of the benefits of 3-D graphics have more to do with science fiction than with science. At NASA's Ames Research Center, visitors who put on special computerized gloves and helmets can actually experience what it would be like to explore various 3-D worlds -- a space station orbiting the earth, for example, or the landscape of Mars. The gloves are equipped with magnetic position trackers and fiber-optic sensors that telegraph every movement of the hand directly to the machine. The helmet is equipped with a pair of stereoscopic TV projectors, one for each eye, that are carefully coordinated so that a slight turn of the head to the right will shift the entire synthetic world to the left.

"That's the key to the illusion," says Lanier of VPL, which supplies NASA with its DataGloves, and has developed its own EyePhones goggles and full-body DataSuit. "Once you reach a certain threshold, your brain suddenly flips into believing that the virtual world is the real world." Lanier used the power of this illusion to teach himself to juggle. Donning Data-Gloves to control some computer-generated balls, he began tossing them around in slow motion and then gradually sped up the simulation until he was juggling at a normal pace. Lanier envisions the day when architects will not just wander around computer- generated buildings but will also move walls and rearrange windows simply by reaching out and grabbing them. Eventually, he predicts, couples will be able to visit artificial tropical islands together. What they do there will be limited only by their imagination -- and the power of their computers.