A pioneering application of virtual reality was the NASA Windtunnel [Bryson92]. A 3D workstation generates flow field visualizations. The user interacts with the simulation via a BOOM display and a data glove. The data glove effectively acts as a source of "smoke" allowing the user to observe local flow lines. The computation of unsteady flow visualization occurs in real time and the use can view the dynamic scene from many points of view and scales, however unlike a real user in a flow the presence of the user does not disturb the flow. According to a a description of the system:
Since fluid dynamic phenomena occur over a large range of scales (several orders of magnitude in space), navigation through the virtual environment is more difficult than, say, architectural walkthrough. Thus, in addition to `standard" viewing capabilities sensitive to head position and head orientation, our virtual environment lets the user rapidly change his or her scale, or the scale of the environment. Relative to the environment, a user can shrink to become completely surrounded by some small vortex or grow so that the entire flow field fits in one hand.
FIGURE 4. NASA Virtual Wind Tunnel
As an extension to the original virtual wind tunnel NASA has continued development by examining feasibility of a distributed virtual windtunnel [Bryson92b]. In this prototype several users can interact with the data being computed on a Convex C3240 computer and visualization on a Silicon Graphic workstation. With the resulting scenario two users can view the same flow visualization and each can observe the flow lines (rakes) injected by the other.