What are virtual environments?

Virtual environment displays arose from vehicle simulation and teleoperations technology of the 1960s. They are interactive, head-referenced computer displays that give users the illusion of displacement to another location. Different terms have been applied to the illusion. Some, like the oxymoronic "artificial reality" and "virtual reality", suggest much higher performance than current technology can generally provide. Others, like "cyberspace" are puzzling neologisms. Expressions like "virtual worlds" and "virtual environment" seem preferable because they are linguistically conservative, relating to well-established terms like virtual image. In fact, we can define virtual environments as interactive, virtual image displays enhanced by special processing and by nonvisual display modalities, such as auditory and haptic, to convince users that they are immersed in a synthetic space. Why are these displays useful? Who uses them? How are they developed? The article addresses these and other questions related to this emerging technology.>