degrees of freedom.(Technology Information)

NEW DISPLAY TECHNOLOGIES OFFER UNENCUMBERED VIEWING AND MANIPULATION OF STEREO 3D IMAGES

A heightened sense of 3D has been available for some time to wearers of shutter glasses and head-mounted displays, but manufacturers are only starting to commercialize display technology that does not require users to wear special viewing devices. These autostereoscopic displays, as they are called, generate separate images for the left and right eyes and project them to the observer through filtering screens, creating a stereoscopic--or parallax--view. By making 3D computer imaging a more seamless part of everyday work and play, autostereoscopic systems should be attractive for a wide range of applications, including molecular modeling, scientific visualization, medical training, computer-aided design, collaborative design and manufacturing, virtual teleconferencing, gaming, and virtual portraiture.

But while existing commercial 3D autostereoscopic displays can produce images with impressive depth qualities, the "sweet spots"--the areas that provide satisfactory views of the stereo 3D image--are limited, thus observers must remain relatively still. Now, research labs around the world are working on prototypes that track the movements of observers and provide them with individual 3D perspectives of an object as they move about. New systems also are under development that integrate haptic and autostereoscopic technologies, making it possible for users to touch, manipulate, and alter stereo 3D images.

Freedom of Movement

At New York University's Media Research Laboratory, computer scientists have built an autostereoscopic display that allows a single viewer to move freely while retaining an undistorted perspective of the simulated image. The 3D effect is visible over an angular volume of 20 degrees both horizontally and vertically and at a distance of 1 to 4 feet from the monitor. Project leader Ken Perlin, a professor of computer science at NYU, believes the system is the first autostereoscopic display to allow free movement within this range.

"It enables a graphic image to assume many of the properties of a true three-dimensional object," Perlin says. "An unencumbered observer can walk up to an object and look at it from an arbitrary distance and angle, and the object will remain in a consistent spatial position."

NYU doctoral researcher Chris Poultney adds, "The effect is as though you are looking at a solid object suspended in front of you, usually centered on the backplane of the display. As you look around the object, features come into view or become obscured, just as you would expect with a real object."