Real-time global illumination is key to enabling dynamic and believable game worlds. GPU-accelerated ray tracing makes this possible; however, framerate and resolution requirements limit the number of traceable rays per pixel, imposing practical limits on current hardware generations. Existing solutions, such as probe-based techniques, approximate the irradiance signal using fewer rays per frame but suffer from reduced details and slow response times to lighting changes. On the other hand, reservoir-based resampling techniques capture higher detail but typically suffer from poorer performance and increased noise.

In this presentation, Guillaume Boisse, Senior Graphics Programmer at AMD, will walk through the practical implementation of a solution [PDF, 8MB] aimed at making the most of every sample by caching the estimated radiance into a cache hierarchy used for both sampling and filtering. He will show how this approach allows for highly performant, high-quality, dynamic, and leak-free global illumination without requiring any content pre-processing, thus enabling easy integration into existing real-time rendering pipelines.

The YouTube video below shows a PREVIEW of a pre-release version of our GI-1.0 solution including a sneak peek of glossy reflections.