Virtual Reality

At first, Engelbart's ideas were dismissed, but by the early 1960s other people were thinking the same way. Moreover, the time was right for his vision of computing. Communications technology was intersecting with computing and graphics technology. The fi rst computers based on transistors rather than vacuum tubes became available. This synergy yielded more user-friendly computers, which laid the groundwork for personal computers, computer graphics, and later on, the emergence of virtual reality.
A natural consumer of computer graphics was the entertainment industry, which, like the military and industry, was the source of many valuable spin-offs in virtual reality.

A goal of scientific visualization is to capture the dynamic qualities of systems or processes in its images. In the 1980s, borrowing and as well as creating many of the special effects techniques of Hollywood, scientific visualization moved into animation. In 1990, NCSA's award-winning animation of smog descending upon Los Angeles influenced air pollution legislation in the state. This animation was a compelling testament of the value of this kind of imagery.

But animation had severe limitations. First, it was costly. After months of elaborate computer simulations, the smog animation itself took 6 months to produce from the resulting data; individual frames took from several minutes to an hour. Second, it did not allow for interactivity -- that is, for changes in the data or conditions governing an experiment that produce immediate responses in the imagery. Once completed, the animation could not be altered.

Scientists wanted interactivity. So did the military, industry, business, and entertainment. The demand for interactivity pushed computer visualization to the limits, towards virtual reality.

Source: http://archive.ncsa.illinois.edu/Cyberia/VETopLevels/VR.History.html