Intelligent systems and simulated environments require intuitive interfaces for man-machine interaction. One of the most important components of such a system is to interactively display the data in response to the user. Interactivity is defined as at least 20 updates per second for visual display.

In this paper, we give a brief overview of our work on interactive display of complex datasets. We use algorithms based on visibility culling that do not render the primitives that are not visible to the viewer from a viewpoint. We augment them with level-of-detail representations or multi-resolution modeling techniques which use different approximations of an object in the scene based on its distance from the viewpoint. We also utilize out-of-core techniques that use a limited memory footprint and predictive schemes to load only a portion of the scene that is used by the underlying rendering algorithm. We also present techniques to integrate these approaches and analyze the trade-offs. We have also developed parallel techniques that utilize multiple CPUs and GPUs (graphics processing units) for fast display. The resulting systems have been used for interactive walkthrough of complex datasets including a powerplant model composed of 13 million triangles, Double Eagle Tanker model composed of 82 million triangles and portions of a Boeing 777 model consisting of more than 470 million triangles.