The holodeck ray cache: An interactive rendering system for global illumination in nondiffuse environments

We present a new method for rendering complex environments using interactiv e, progressive, view-independent, parallel ray tracing. A four-dimensional holodeck data structure serves as a rendering target and caching mechanism for interactive walk-throughs of nondiffuse environments with full global i llumination. Ray sample density varies locally according to need, and on-de mand ray computation is supported in a parallel implementation. The holodec k file is stored on disk and cached in memory by a server using a least-rec ently-used (LRU) beam-replacement strategy. The holodeck server coordinates separate ray evaluation and display processes, optimizing disk and memory usage. Different display systems are supported by specialized drivers, whic h handle display rendering, user interaction, and input. The display driver creates an image from ray samples sent by the server and permits the manip ulation of local objects, which are rendered dynamically using approximate lighting computed from holodeck samples. The overall method overcomes many of the conventional Limits of interactive rendering in scenes with complex surface geometry and reflectance properties, through an effective combinati on of ray tracing, caching, and hardware rendering.