Issue: Volume: 23 Issue: 11 (November 2000)

Up Close and Virtual

Looking back over the past year, if I had to pick the computer graphics technology that was the most impressive, both in terms of degree of innovation and impact on the industry, my vote would be for the host of new 3D displays that have recently sprung from research labs around the world. After trying out many of these new systems in the Emerging Technologies pavilion at Siggraph 2000, I discovered that developers have achieved breakthroughs on several fronts. Here are some noteworthy examples

Screen displays:
One remarkable new screen system is the Barco/SGI Ultra High-Resolution Visualization Center, a "portable" 18-foot-long projection screen that curves around the viewer and fills his or her entire field of view. As I stood immersed in a 3D visualization of seismic data used for oil exploration, I felt like I was in a mini Imax theater, except that the image quality and the resolution were superior. I also had a chance to try out the Panascope, a system developed at the University of Montreal that takes the concept of immersive displays to the extreme by mapping CG images onto a 360-degree panoramic screen. Standing inside the 4-foot diameter doughnut-shaped viewing area, I was surrounded by a virtual environment that I could navigate by voice command.

Autostereoscopic displays: Viewing 3D objects in stereo-so they appear to be floating in mid air-has been possible for a number of years. But most techniques rely on special glasses that filter and display different views of an image for the user's right and left eye to create the stereoscopic effect. Some systems eliminate the need for special glasses by focusing filtered images directly to the viewer's eyes, but they work only if the person's head remains perfectly still. This year, Ken Perlin and a team at New York University introduced a clever, glasses-free device that combines an image-filtering technique with a head-tracking system to dynamically adjust the image so users can continue to see the stereoscopic view while changing positions. The system I tried used an infrared eye tracker that allowed me to rotate my head and move around freely yet still see a stereo 3D image-a medical visualization-hovering about 4 inches in front of a rear-projection screen.

Direct retinal imaging: This novel apparatus from Osaka City University in Japan fires low-intensity laser beams onto the retina of each eye to create 3D stereoscopic images without the use of screen projection. When I placed my head between two lasers positioned at the periphery of my vision, a simple line drawing of a red tether ball was projected (harmlessly) into my eyes so it appeared to be coming closer to me and then moving away as it whirled around a pole. Because the real world is visible behind the image, this technology has great potential for augmented-reality applications in which computer images and information are superimposed onto real objects and scenes.

"The new stereoscopic systems are extremely important," says Jeff Close, Emerging Technologies chair, "because for the first time in the history of this technology, people will be able to walk up to some type of viewing area and see 3D objects floating in mid air in front of them without wearing special eyewear." And, in a broader sense, all of these advances in displays are significant because they help redefine how we interact with computers, moving us closer to a point where computers will accommodate us rather than require us to conform to them.

Phil LoPiccolo: Editor-in-Chief