TECHNOS

January 6, 2009

TECHNOS QUARTERLY Spring 1994 Vol. 3 No. 1

Virtual Reality Lexicon and Litmus Test

By Joan Lewis

Lexicon

Following the virtual reality (VR) saga as it unfolds will be a lot more enjoyable if you understand some of the jargon and are able to decode a particular set of acronyms.

Cathode ray tubes (CRTs). In VR, CRTs are tiny versions of the TV receivers you have in your home. CRT technology is one of the two currently available display options for HMDs. CRTs provide the best resolution, but you give up color. Color TVs that tiny can't be made yet.
Cybernaut. As you wander around cyberspace—maybe on the Internet through your computer or around a virtual environment through an HMD—you are a cybernaut.
Cyberspace. This term, coined by author William Gibson in his 1984 novel Neuromancer, is broadly used to describe a graphic representation of data abstracted from the banks of every computer in the human system. Cyberspace is sensation of place without physicality—an electronically linked network of the information held in human minds and computer banks, worldwide.
Data glove. VPL's DataGlove is a trademark product, whose name has come to stand for the whole genre of sensory glove-input devices to a VR engine computer. Sensory gloves are built with sensors that allow the wearer to direct a virtual agent and manipulate objects in the VR environment. “Output tactile gloves” and “sensory full-body suits” that will allow the computer to transmit information to the wearer via the sense of touch are under development.
Fly. A term sometimes used in discussing a VR experience that lets the user pass quickly, or fly, through a virtual environment. Some low-end VR systems are referred to as “fly-only environments”—the flyer can direct his or her route but cannot interact with or change the virtual environment.
Head mounted displays (HMDs). These are the stereoscopic screens, about one inch in diameter, on which you view the computer-generated virtual world. The screens, one for each eye, may be CRTs or LCDs. The HMD itself may resemble a helmet with a visor, goggles, or clunky glasses. As technology improves, HMDs are becoming less bulky. More than 17 are currently on the market.
Liquid crystal displays (LCDs). LCD technology is one of the two current display options for HMDs. LCDs in VR are mini versions of the screens you see on portable computers, game systems, and digital watches.
Real time. When the actions of a VR user's virtual agent occur simultaneously with those of the VR user, that is real time. Real time is desired. When you do not achieve real time, you experience “lag”—a slight time-lag between what you do and what you see. Lag can make you sick.
Virtual agent. A computer-generated character who acts on behalf of the user in a virtual (computer-generated) environment. If you raise your real hand, you see your virtual agent's hand raise in the VR world.
Virtuality. The virtual environment that the VR user perceives.
VR data base. You cannot build a VR environment without a data base. If you want a VR version of a medieval city scene, you must first compile data that includes all the details: Appearance of the buildings, surroundings, objects, people, etc., that inhabit that environment, as well as data on how those people and objects react to stimuli.
VR engine. The computer that runs the VR environment. Complex, interactive environments require a much more powerful engine than do fly-only environments.

Litmus Test

Jaron Lanier, founder of VPL Research, Inc., is credited with coining the term virtual reality, which originally described the use of computer-generated images to give the user the illusion of participating in fabricated events in a fabricated world. The two qualifying characteristics of this “true” VR are total immersion in the fabricated world and ability to interact with and change that world. But as its offshoots and parallel technologies develop and its commercial exploitation becomes rampant, VR is becoming a catchall term for several distinctly different experiences. Is there a litmus test to certify legitimate VR from pretenders going by that name in the marketplace? Not really—definitions are still hotly contended. Following are a few technologies that sometimes carry a VR label.

3-D computer graphics. Three-dimensional representations, often with limited animation. They sometimes require the viewer to wear special glasses to get the full effect.
Experience theaters. In these modern movie houses, moviegoers view films on huge curved screens and are surrounded by stereophonic sounds. Granted, that's not so new—but now your theater seat moves to match the action.
Interactive video. The user views a typical 2-D film but can change the course of that film by exercising options, sometimes just by touching the computer screen.
MUDs (Multi-User Dungeons). Sometimes referred to as text-based VR adventures, these simulation games are carried out in the cyberspace of the Internet. You input and receive only text messages; the vision is all in your mind's eye.
Telepresence. A computer system under development that allows the remote manipulation of equipment or instruments. One example: Information regarding the movements of a doctor working in a VR environment in one location could be fed electronically to a robotic arm in another location. The robotic arm, mimicking the doctor's actions, would actually work on the real patient.

Return to Virtual Reality: Ready or Not! TECHONS Quarterly article.