Virtual Reality

Overview

Virtual reality (VR) is one of the hottest research and development areas in the computer industry today. Its potential applications range from medical imaging and interior design to intercontinental videoconferencing and the exploration of future worlds. There are a number of ways in which virtual reality technology can be employed; its underlying premise, however, is to create more intuitive ways for humans and computers to work together.

VR is often thought of as new technology, but its development actually dates back almost 50 years to flight simulators built by the aircraft industry and the U.S. Air Force during and after World War II. Student pilots learned how to maneuver airplanes by manipulating the controls in specially built airplane cockpits. These cockpits, which were actually removed from the airplanes themselves, were mounted on movable platforms that tilted and rolled based on the pilot's actions on the controls.

VR's future was also influenced by film techniques such as stereoscopic, or 3-D cinema, and several wide-screen systems that Hollywood filmmakers were experimenting with during the early 1950's. Cinerama, the best-known of these technologies, sought to expand the movie-going experience by filling a larger portion of the audience's visual field. Three cameras, shooting from slightly different angles, were used to film each scene in a Cinerama movie. The film was then synchronized and projected onto three large screens that curved inward, wrapping around the audience's peripheral visual field. This technology proved too costly to be embraced by most commercial theaters, but the theory of visual immersion would go on to become an important VR element.

Cinerama excited a young documentary filmmaker named Morton Heilig, who believed the future of cinema lay in creating films that could employ the human senses of sight, sound, scent, and feel. He diagrammed the various elements he felt were necessary to create that total illusion, such as the brain's sensory channels and the body's motor network. He called his end product "experience theater."

Heilig's research led to "Sensorama," a VR-type arcade attraction he designed and patented in 1962. Sensorama simulated all the sensory experiences of a motorcycle ride by combining 3-D movies, stereo sound, wind, and aromas. By gripping the handlebars on a specially equipped motorcycle seat and wearing a binocular-like viewer, the "passenger" could travel through scenes including California sand dunes and Brooklyn streets. Small grills near the viewer's nose and ears emitted breezes and authentic aromas. Sensorama was extremely complex for the arcade environment, and funding never materialized for the simplified version Heilig later developed, but his vision of a medium that combined multisensory artificial experiences is fast becoming a reality.

Cinerama and Sensorama gave VR two of its most important theoretical and visual legacies, but artificial intelligence research conducted in the late 1950's and 1960's largely formed the scientific platform for VR as it exists today.

One area of artificial intelligence research explored building better interfaces between people and machines. In the early 1960's a graduate student named Ivan Sutherland presented a Ph.D. thesis in this area that demonstrated a new way to interact with computers. Sutherland believed that display screens and digital computers could offer a means of gaining familiarity with concepts not realizable in the physical world by providing a window, or looking glass of sorts, into the mathematical wonderland of a computer.

Sketchpad, the program Sutherland developed and described in his thesis, used computer technology to create images from abstract ideas. Using Sketchpad and a penlike device, a computer could create sophisticated images on a display screen resembling a television set. The system responded by rapidly updating the drawing so that the relationship between the user's action and the graphical display was clear. Computer-aided design (CAD) grew out of Sutherland's thesis and became one of the most powerful components of VR development in the 1990's.

Sutherland next focused on developing technology that would allow computer users to actually enter the world of computer-generated graphics. In 1965, with support from the Department of Defense's Advance Research Projects Agency (ARPA) and the Office of Naval Research, Sutherland unveiled the head-mounted display (HMD), which took users inside a three-dimensional world by limiting visual contact to the displays shown by small computer screens mounted in binocular glasses. It became a cornerstone of VR technology.

In the late 1960's and 1970's, research on a number of fronts formed the basis of VR as it appears today. Projects such as the Aspen Movie Map, developed by a group of researchers including Andrew Lippman, Michael Naimark and Scott Fisher at the Massachusetts Institute of Technology (MIT), showed video images of Aspen, Colorado, that visitors could actually navigate by indicating their choices on a touch-sensitive display screen. Videoplace, one of several experimental artistic environments designed by arts scholar Myron Krueger, used computers to create what Krueger called "artificial reality," allowing viewers to interact with computer-generated graphics and projected images.

In the mid-1980's, the different technologies that enabled the development of VR converged to create the first true VR system. Researchers at NASA's Ames Research Center in Mountain View, California, were charged with creating an affordable pilot training system for manned space missions. Over several years, the project pooled the resources of such individuals as Scott Fisher, who had continued his research on virtual environments after the Aspen Movie Map project; Stephen Ellis, a University of California-Berkeley researcher who had studied how human beings interact with their environments; Michael McGreevy, a UCB graduate student who was also interested in immersive displays; and Warren Robinett, a programmer who had worked on educational software at Atari.

The conjoining of their efforts, as well as the contributions of other researchers and companies, led to the development of the Virtual Interface Environment Workstation. It was the first system that combined such standard VR elements as computer graphics and video imaging, 3-D sound, voice recognition and synthesis, and a head-mounted display. A data glove, based on an invention designed to play air guitar, completed the system.

From there, it was only a matter of time before VR programs began appearing in settings ranging from virtual reality theme parks to operating rooms, largely aided by products developed by Jaron Lanier, whose programming language operated the first data glove at the NASA research center. Lanier's company, VPL Research, was the first company to focus its efforts on developing products for the infant VR industry, and provided the headgear and gloves used in many early VR applications.

Most head-tracking displays resemble helmets, from which viewing devices are displayed. Instrumented gloves use sensors passing over joints in the user's hand to measure the position of the fingers and hand.. Special devices called trackers are attached to this equipment. They translate movements into coordinates, which are then fed back to the computer so that the model of the virtual world can be appropriately changed.

It is also possible to experience virtual worlds without using immersion devices. New technology such as The PHANToM, developed at the MIT Artificial Intelligence Lab, creates the illusion of touching virtual objects. Projected systems, often used in museums and for medical displays, take an image of the user's motions and display it with other images on a large screen. Simulation VR, widely found in VR game arcades and parks, use a combination of video monitors and movable pods or platforms to create virtual experiences. The Magic Edge, for example, a combination restaurant/bar in Mountain View, California, offers virtual reality flight simulators that let would-be fighter pilots battle each other over a fully rendered virtual landscape. It is even possible to enter virtual worlds through a desktop computer, although the high cost of the equipment involved makes it difficult to create a truly immersive VR event.

In 1984, science fiction writer William Gibson coined the term "cyberspace," which described a future world created by the networking of multiple VR systems and environments. As computer systems get faster, less expensive and more powerful, virtual reality systems will do so as well and will increasingly become a part of everyday life. The world that Gibson imagined will be more than just a writer's dream.

Related Resources

Virtual World Creation

Entertainment

Sources

Credits

--Contributed by Sonia Weiss
--WebSite Design by Gerhard Wiegand
--the crew
--Film footage courtesy of NASA.

[ Home   |  Feature Article | Article Index | Search ]

[ Feedback | Crew ]