Virtual Reality: An Overview. ERIC Digest.
by Franchi, Jorge
Virtual Reality (VR), a technology that began in military and university
laboratories more than 20 years ago, may be called Artificial Reality,
Cyberspace, or Synthetic Reality. VR is a computer-created sensory experience
that allows a participant to believe and barely distinguish a "virtual"
experience from a real one. VR uses computer graphics, sounds, and images
to reproduce electronic versions of real-life situations.
Virtual Reality is not a computer, but a technology that uses computerized
clothing to synthesize reality. Most current VR systems provide only visual
experiences created by computer-assisted design (CAD) or other graphics/animation
systems, but researchers are working on interface devices that add sound
and touch. Eventually, VR may be delivered through direct computer-to-brain
HOW DOES VIRTUAL REALITY WORK?
A breakthrough in Virtual Reality came with the development of a head-mounted
display with two tiny stereoscopic screens positioned just a few inches
in front of the eyes. The most popular VR system is one designed by field
pioneer, Jaron Lanier (1989). The system features a head-mounted display
called the EyePhone. Users also wear a DataGlove that generates movement
and interaction in the virtual environment's estimated system price: $205,000.
Movement in Cyberspace is simulated by shifting the optics in the field
of vision in direct response to movement of certain body parts, such as
the head or hand. Turn the head, and the scene shifts accordingly. The
sensation is like being inside an artificial world the computer has created.
The EyePhone uses a set of wide-angle optics that cover approximately
140 degrees, almost the entire horizontal field of view. As the user moves
his head to look around, the images shift to create an illusion of movement.
The user moves while the virtual world is standing still. The glasses also
sense the user's facial expressions through embedded sensors, and that
information can control the virtual version of the user's body.
A group at NASA developed a system of helmet, glove, and a monochrome
three-dimensional reality. The DataGlove, a key interface device, uses
position tracking sensors and fiber optic strands running down each finger,
allowing the user to manipulate objects that exist only within the computer
When the computer "senses" that the user's hand is touching a virtual
object, the user "feels" the virtual object. The user can pick up an object
and do things with it just as he would do with a real object. The DataGlove's
most obvious application will be in robotics, particularly in the handling
of hazardous materials, or by astronauts to control robot repairers from
the safety of a spaceship, or from a space station, or even from Earth.
APPLICATIONS OF VR
Applications for VR are many. Surgeons may soon use VR to "walk" through
the brain or rehearse a surgical operation on a virtual patient. Just as
flight simulators are now an integral part of pilot training, so surgical
simulators will revolutionize medical training.
VR now makes possible telepresence, scientific exploration, and discovery.
For example, the Jason Project for school children features both telepresence
(the feeling of being in a location other than one's actual location) and
teleoperation (controlling a robot submarine) (McLellan, 1995). The Jason
Project, now in its sixth year, was designed to generate excitement about
studying science, mathematics, and technology. NASA has a telepresence
educational program that uses the Telepresence-controlled Remotely Operated
underwater Vehicle (TROV) deployed in Antarctica. By means of distributed
computer control architecture developed at NASA, school children in classrooms
across the United States can take turns driving the TROV in Antarctica.
Someday scientists expect to explore celestial bodies and check out
lakes beneath the Antarctic ice pack using VR applications. Disabled persons,
through prosthetic interfaces, may one day use telerobotics to do tasks
that are now only a dream; three-D sound may one day provide great applications
for the blind.
Whether VR can be an effective tool for education or training depends
partly on one's definition of VR and partly on one's goal for the educational
experience. It may not be worth the cost if the goal of the educational
experience is simply to memorize facts. However, if the goal of the educational
experience is to foster excitement about a subject, or to encourage learning
through exploration, or to give students a taste of what it is like to
be a research scientist, then VR may be worth the expense.
DRAWBACKS OF VR
Despite enormous potential practical application, VR, in its current
state, has drawbacks. It is still extremely expensive, the graphics are
still cartoonish, and there is still a slight, but perceptible time lag
between the user's body movements and their translation in Cyberspace.
The equipment the user must wear, such as head gear, gloves, and other
devices, needs refinement. At this early stage in the development of VR,
no one knows what the long-term effect of using head-mounted displays might
be on human eyes or what the possible psychological effect might be from
spending too much time in Cyberspace. People using VR head gear sometimes
complain about chronic fatigue, a lack of initiative, drowsiness, irritability,
or nausea after interacting with a virtual environment for a long time.
We do not know how much each of these symptoms depends on the characteristics
of the VR systems themselves, or on the characteristics of the individuals
using the systems.
THE FUTURE OF VR AND FUTURE POLICY DIRECTIONS
The Electronic Industries Association, a Washington, DC-based trade
group representing hundreds of defense contractors nationwide, conducted
a study that projected annual sales of virtual reality technology. Results
project growth in defense and nondefense areas, ranging from about $100
billion in 1994 to $280 billion in 2003.
The National Research Council (NRC), conducted a study on Virtual Reality
and its applications. "The federal government has a rare and important
opportunity to foster careful planning for its research and development,"
concludes the committee in its report (Durlach, 1995). Among the committee's
--Develop a comprehensive national information system to provide coverage
of research activities and results on virtual environments in a user-friendly
--Establish a few national research and development teams, each focusing
on a specific application. The teams could be made up of members from government,
industry, and academia, and funding could be provided jointly by both the
federal government and the private sector.
--Federal agencies and offices could consider experimenting with VR
technology in their own workplace.
--The federal government could also explore the opportunities for early
development of standards to promote compatibility of hardware, software,
and networking technology.
Ten years ago VR was a science-fiction fantasy. Today it is a developing
technology seen primarily in research labs, theme parks, and trade shows.
Tomorrow it may be as common as television. Lanier (1989) likes to say
that "VR is a medium whose only limiting factor is the imagination of the
Ditlea, S. (1989, November). Inside artificial reality. "PC Computing,"
Durlach, N., & Mavor, A. S. (Eds.). (1995). "Virtual reality: Scientific
and technological challenges." Washington, DC: National Academy Press.
Emery, G. (1990, December). Close encounter of the virtual kind. "Insight,"
Foley, J. D. (1987). Interfaces for advanced computing. "Trends in Computing,"
62-67. (Reprinted from the October 1987 issue of "Scientific American,"
257(4), 126-135. (EJ 359 987)
Fritz, M. (1990, June). Eyephones, datasuits, and cyberspace. "CBT Directions,"
28(2), 11-17. (EJ 420 905)
Fritz, M. (1991, February). The world of virtual reality. "Training,"
Furness, T. A. (1988, May). Harnessing virtual space. "Society for Information
Display (SID) International Symposium, Digest of Technical Papers," (1st
edition). Playa del Rey, CA: Society for Information Display.
Gay, E. (1994, Winter). Is virtual reality a good teaching tool? "Virtual
Reality Special Report," 1(4), 51-59.
Helsel, S. K. (Ed.). (1991, January/February). Definitions: Plethora
of definitions. "Virtual Reality Report," 1(1), 3.
Interview with Jaron Lanier. (1989, Fall). "Whole Earth Review," 64,
McLellan, H. (1995, January/February). Virtual field trips: The Jason
project. "VR World," 3(1), 49-50.
Merril, J., Millman, A., Raju, R., & Roy, R. (1995, January/February).
Window to the soul. "VR World," 3(1), 51-53.
Merril, J., Roy, R., Merril, G. & Raju, R. (1994, Winter). Revealing
the mysteries of the brain with VR. "Virtual Reality Special Report," 1(4),
Weimer, D., & Ganapathy, S. K. (1989, May). "A synthetic visual
environment with hand gesturing and voice input." Holmdel, NJ: AT&T
Zimmerman, T. G., Lanier, J., Blanchard, C., Bryson, S., & Harvill,
Y. (1987). "A hand gesture interface device." Redwood City, CA: VPL Research,