Many believe that Morton Heilig was the first person to attempt to create what we now call virtual reality (Packer & Jordan, Eds., 2001), and in 1955 he wrote a paper called “The Cinema of the Future,” which outlined a framework for simulating a multi-sensory cinematic experience. Heilig’s goal was to present to the audience the illusion and sensation of a first-person experience such that they truly felt immersed in the media (Heilig, 1955). His “Sensorama” machine attempted to stimulate all five senses in the following breakdown: Sight = 70%, Hearing = 20%, Smell = 5%, Touch = 4% and Taste = 1% (Heilig, 1955). While his devices never became popular successes, his work was an inspiration to future virtual reality engineers.
In 1963, a twenty-two year old graduate student at MIT named Ivan Sutherland astonished colleagues with his work in interactive computer graphics. Sutherland was a visionary, and in 1966, still several years before the introduction of the personal computer, he implemented the first head-mounted display (Packer & Jordan, Eds., 2001). According to Sutherland, the ultimate computer-generated display is “a room within which the computer can control the existence of matter” (Sutherland, 1965), but short of this, he was a pioneer in advancing the immersive properties of virtual reality technology.
Heilig and Sutherland, along with many others, have helped to bring about a keen interest in virtual reality, both in cultural and academic circles. It seems that society has tremendous zeal for the idea of full sensory immersion – to explore an alternate world outside of one’s own body. But what is virtual reality, besides, perhaps, an oxymoron? Much of the contemporary notion of virtual reality comes from the work of Scott Fisher in the early 1980’s, whose work was influenced by Heilig, Sutherland and many other predecessors (Packer & Jordan, Eds., 2001), but a concrete definition is hard to come by. The term virtual reality was actually coined by Jaron Lanier in the mid 1980’s, who went on to create VPL Research Inc., out of which came such trademark VR equipment as the DataGlove, DataSuit, and the Eye Phones (Bacard, 1993). Many researchers believe that virtual environment is a better phrase (Vince, 1998), but most people would agree that computers are inextricably involved.
“Virtual Reality: a medium composed of highly interactive computer simulations that sense the user’s position and replace or augment the feedback of one or more senses – giving the feeling of being immersed, or being present in the simulation.” – (Sherman & Craig, 1995)
Howard Rheingold defines virtual reality as an experience where the participant is “surrounded by a three dimensional computer-generated representation, and is able to move around in the virtual world and see it from different angles, to reach into it, grab it, and reshape it” (Rheingold, 1991). Both of these definitions speak to the fact that virtual reality is an immersive experience, one in which the user can interact with the computer-generated environment in real-time. In the quest to produce an effective and satisfying virtual reality space, many interesting and complex technologies have emerged over the last few decades.
A variety of different machines and devices have been developed over the years in the advancement of virtual reality technology. Since Ivan Sutherland created the first head-mounted display (HMD) back in 1963, a number of companies have developed similar versions in an attempt to design the ultimate VR experience. HMD’s were the first devices to be used in commercial VR applications, such as virtual reality arcade games (Vince, 1998, pg. 26). A typical HMD contains two LCD elements mounted on a helmet that fits over the participant’s head. The LCD screens are quite close to the eyes in order to enhance the sense of immersion by blocking out the outside world. The horizontal field of view is usually around 60o for each eye, with a vertical field of view of 45o (Vince, 1998, pg. 84).
The binocular omni-oriented monitor (BOOM) display is a device which fits over the participant’s eyes, but which is supported by a counterbalanced arm to eliminate the heavy and cumbersome helmets that are typical of HMD’s. The user can be either sitting or standing, and the 3D perspective in the virtual environment is calculated by the movement of the arm’s joint angles (Vince, 1998, pg. 86).
At SIGGRAPH ’92, a VR device was exhibited by the University of Illinois at Chicago called the CAVE (Cave Automatic Virtual Environment). It was initially designed as a scientific visualization system by the Electronic Visualization Lab (EVL) at UIC, but has since been used for many other applications, immersive entertainment among them. The CAVE is a 10x10x10 ft. cube made up of three rear-projection screens for walls and a top-down projection screen for the floor. The projectors are hooked up to high-end graphics computers, such as an SGI Onyx2 Infinite Reality, which generate the 3D graphics in real-time for a 1280×512 stereo display at 120 Hz (Cruz-Neira, 1993). For interactivity, the user’s head and hand are tracked with electromagnetic sensors, or a 3D-wand can be used. The alternate left and right eye displays – needed to produce the pop-up 3D effects – are synchronized with light-weight LCD stereo shutter glasses.
The benefits of the CAVE are that it achieves a large angle of view, has high resolution (HDTV to twice HDTV) color images, and can accommodate multiple people at the same time (although with only person controlling the interactivity) (Cruz-Neira, 1993). Having the large-scale projection walls of the CAVE means that the projection plane does not rotate with the viewer; this reduces errors from rotational tracking noise and latency typical of wearable devices such as HMD’s and BOOM’s (Cruz-Neira, 1993). The CAVE is also a floor-to-ceiling display, which greatly improves one’s immersion into the manufactured environment.
References:
Bacard, Ander. “Welcome to virtual reality,” Humanist, Vol. 53, Issue 2, Mar/Apr 1993. pp42-43.
Cruz-Neira, Carolina, Sandin, Daniel and Thomas DeFanti. “Surround-Screen Projection-Based Virtual Reality: The Design and Implementation of the CAVE.” SIGGRAPH 93 Paper.
Heilig, Morton. (1955) “The Cinema of the Future,” in Packer, Randall and Ken Jordan, Eds., Multimedia: From Wagner to Virtual Reality. New York: W.W. Norton & Company. 2001.
Packer, Randall and Ken Jordan, Eds., Multimedia: From Wagner to Virtual Reality. New York: W.W. Norton & Company. 2001.
Rheingold, Howard. Virtual Reality. Summit, New York, 1991.
Sherman, William R. and Alan B. Craig. “Literacy in Virtual Reality: a new medium,” Computer Graphics, Vol. 29, No. 4, ACM Press, November 1995.
Sutherland, Ivan. (1965) “The Ultimate Display,” in Packer, Randall and Ken Jordan, Eds., Multimedia: From Wagner to Virtual Reality. New York: W.W. Norton & Company. 2001.
Vince, John. Essential Virtual Reality Fast. London: Springer-Verlag London Limited, 1998.
