Welcome to virtual reality, a computer-generated world that humans can experience and manipulate. In fact, what sets virtual reality apart from other computer graphics is that it's highly interactive and can make an environment more realistic by providing a combination of sensory data--sound, sight and touch.
"As computer processors have become more powerful, as they refine their ability to generate and display data, they allow the user to have more interactive involvement," said David Allison of the Smithsonian. "Early computers were large machines designed to process numerical data, which was fed indirectly by punch cards. From there, we progressed to keyboards and touch screens. Now we can input data directly through physical movement."
A typical virtual-reality setup involves four or five major components. One is a helmet with earphones and goggles containing a tiny video monitor for each eye, providing three-dimensional visuals. The field of vision is completely filled by computer-generated images, which appear real but are merely projections. Later generations will "write" images directly to the eye, providing a sharper picture and eliminating the need for goggles.
The second component is a "joystick" or control device that directs movement. The third is a small electromagnetic sensor suspended above the user, which constantly monitors the locations of the helmet and joystick and transmits information back to the computer. The computer generates sounds and graphics piped into the helmet and keeps track of the user's position in the artificially-generated world.
The idea of using computers to create an environment dates back to the late 1960s. A computer scientist at the University of Utah, Dr. Ivan Sutherland, published a paper in 1968 describing a helmet that could project images in front of the viewer's eye. He called it "The Ultimate Display."
Around the same time, Thomas A. Furness, a young scientist at Wright-Patterson Air Force Base in Ohio, began to work on better cockpit technology for pilots.
"I was trying to solve problems of how humans interact with very complex machines," said Furness. "In this case, I was concerned with fighter-airplane cockpits."
Aircraft were becoming so complicated that the amount of information a fighter pilot had to assimilate from the cockpit's instruments and command communications had become overwhelming. The solution was a cockpit that fed 3-D sensory information directly to the pilot, who could then fly by nodding and pointing his way through a simulated landscape below. Today, such technology is critical for air wars that are waged mainly at night, since virtual reality replaces what a pilot can't see with his eyes.
"To design a virtual cockpit, we created a very wide field of vision," said Furness. "About 120 degrees of view on the horizontal as opposed to 60 degrees."
In September of 1981, Furness and his team turned on the virtual-cockpit projector for the first time. "I felt like Alexander Graham Bell, demonstrating the telephone," recalled Furness. "We had no idea of the full effect of a wide-angle view display. Until then, we had been on the outside, looking at a picture. Suddenly, it was as if someone reached out and pulled us inside."
This ability to engulf the user is one of the outstanding features of virtual reality. "Virtual reality replaces the real world," said Furness. "You can fly in it, walk in it, manipulate objects in it--even though there's nothing there."
For the past few years, the technology has been a popular addition to video arcades, allowing users to experience games more deeply. But in spite of its mindboggling uses, the technology for virtual reality is still at an early stage and offers many possibilities for future applications.
"It can be used to study human behavior," say Allison. "It can test what happens to people when they encounter a certain situation. It can be used to design buildings or construct aircraft. Perhaps the most fruitful application will be in training, such as driver or pilot training, which can be done in a lab instead of the real world."
Moving information around on computers is much less expensive than moving real-life cars, buildings and people, experts note. The technology can save wear and tear on equipment and the environment as well as conserve resources, such as fossil fuels. And many feel that education will be the most exciting application of this space-age technology.
"Virtual reality helps accelerate learning," said Furness. "It gives kids a chance to walk into a textbook, to experience it. A teacher might ask, 'What was it like at the Battle of Gettysburg?' And the students will create a world to explore it."
Medicine is another field ripe for virtual interface. For example, "Computer-Assisted, Stereoactic Neurosurgery" projects a 3-D view of a brain tumor directly to surgeons while they operate. The equipment helps surgeons locate and excise tumors in the brain with greater precision
Virtual reality can also be used to enhance creative abilities and to simplify complex procedures. An architect can "walk" into a design or an engineer can determine if a man's hand will fit behind a panel to reach an outlet--all without the time and expense of constructing the real item. Software can even simulate resistance so engineers can hear and feel when parts bump into each other.
In the future, many envision a global village connected by virtual technology, where people can meet and share the same sensory experience.
"Instead of dialing a telephone number and talking to a person," said Furness, "you'll simply pick up your 'virtuphone' and be instantly transported. You dial a place and your senses would go there. I see virtual reality extending communications to all people, helping to link minds."
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