Distributed interactive ray tracing of dynamic scenes

Recently developed interactive ray tracing systems combine the high performance of todays CPUs with new algorithms and implementations to achieve a flexible and high-performance rendering system offering high-quality, but nonetheless interactive 3D graphics. However, due to its history in offline rendering, interactive ray tracing is usually limited to static scenes and simple walkthroughs. In order to become truly interactive ray tracing must efficiently support dynamic scenes. We present a simple and practical method that allows to interactively ray trace dynamic scenes in a distributed PC cluster environment. Our method separates the scene into independent objects with common properties concerning dynamic updates - similar to OpenGL display lists and scene graph libraries. Three classes of objects are distinguished: static objects are treated as before, objects undergoing affine transformations are handled by transforming rays, and objects with unstructured motion are rebuilt whenever necessary. We present performance and scalability results of our system using a variety of test scenes stressing a wide range of dynamic behaviour.