Title: StarRay - Interactive Ray Tracer

Presenter: Steve Parker, University of Utah


Interactive rendering systems provide a powerful way to convey information, especially for complex environments. Until recently the only interactive rendering algorithms were hardware-accelerated polygonal renderers. This approach has limitations due to both the algorithms used and the tight coupling to the hardware. Software-only implementations are more easily modified and extended which enables experimentation with various rendering and interaction options.

We will explore an interactive ray tracing system designed for current multiprocessor machines. This system was initially developed to examine ray tracing's performance on a modern architecture. We were surprised at just how responsive the resulting system turned out to be. Although the system takes careful advantage of system resources, it is essentially a brute force implementation. We intentionally take the simple path wherever feasible at each step believing that neither limiting assumptions nor complex algorithms are needed for performance and parallelism.

We will demonstrate the system used for rendering tradition computer graphics scenes. We will also discuss how this system is used to visualize large-scale (gigabyte) datasets interactively. To gain efficiency several optimizations are used including a volume bricking scheme and a shallow data hierarchy. These optimizations are used in several different visualization algorithms, and are capable of rendering gigabytes to hundreds of gigabytes of data at multiple frames per second.