Exploring the virtual wind.

Calculations of the direction and speed at which air flows past a complicated, three-dimensional object, such as an airplane, generate huge quantities of data. Conventional two-dimensional graphic images derived from these data often fail to convey the flow's complexity. Now, a team of researchers has assembled a primitive, prototype system for exploring such flow patterns, in effect allowing an investigator to step into and interact with a computer-generated environment.

Steve Bryson and Creon Levit of the NASA Ames Research Center in Mountain View, Calif., used commercially available components to create their prototype system, known as the Virtual Windtunnel.

Through computer graphics and special input devices, the system creates the illusion of being surrounded by a flow. The user looks through a boom-mounted device resembling a diver's mask, which contains two small television sets to produce a wide-angle, stereoscopic image. A computer tracks the viewer's head position and generates the appropriate views. The user also wears a flexible glove fitted with sensors to manipulate the image in various ways. For example, to visualize the direction of flow in a particular region, a researcher can use the glove to specify the starting point for a computer-rendered stream of smoke, and then walk around to see the resulting flow pattern from different angles.

"It puts the computations right in front of the researcher," Bryson says. "It allows real interaction with the data."