Differential Progressive Path Tracing for High-Quality Previsualization and Relighting in Augmented Reality

In this paper we present a novel method for real-time high quality previsualization and cinematic relighting. The physically based Path Tracing algorithm is used within an Augmented Reality setup to preview high-quality light transport. A novel differential version of progressive path tracing is proposed, which calculates two global light transport solutions that are required for differential rendering. A real-time previsualization framework is presented, which renders the solution with a low number of samples during interaction and allows for progressive quality improvement. If a user requests the high-quality solution of a certain view, the tracking is stopped and the algorithm progressively converges to an accurate solution. The problem of rendering complex light paths is solved by using photon mapping. Specular global illumination effects like caustics can easily be rendered. Our framework utilizes the massive parallel power of modern GPUs to achieve fast rendering with complex global illumination, a depth of field effect, and antialiasing.