As you get closer, the column whirs and splits - a disjointed little figure unfolds. The figure gestures to you, then takes off. You follow this strange guide to a dark stairway, winding up inside the cathedral. At the top, a low doorway takes you outside. The city stretches beneath you.
Transparent pathways curl around the dome and lead back to the ground.
You see the little guide far below. He is dancing wildly as a stream of flying letters and books sail past him and whip inside a building. This is a description of an experience in the CAVE virtual reality theatre. Virtual Reality is the art and science of using computers to create three dimensional worlds that users can be immersed in, explore as they please, and interact with in real time. The computer continually updates and redraws the display as users move through the environment.