Interactive virtual reality in simulations: exploring lag time

When coupling supercomputer simulations to "virtual reality" for real time interactive visualization, the critical performance metric is the end to end lag time in system response. Measuring the simulation, tracking, rendering, network, and synchronization components of lag time shows the feasibility of coupling supercomputers with virtual environments for some applications. For others, simulation time makes interactivity difficult. The article analyzes the components of lag for four applications that use virtual environments: Monte-a simple application to calculate /spl pi/ using a parallel Monte Carlo algorithm; Automotive Disk Brake-uses a parallel finite element code to allow users to design and analyze an automotive disk braking system under different conditions; BoilerMaker-lets users design and analyze the placement of pollution control system injectors in boilers and incinerators; Calvin (Collaborative Architectural Layout Via Immersive Navigation)-allows people at different sites to work collaboratively on the design and viewing of architectural spaces.