Towards Interactive Global Illumination Effects via Sequential Monte Carlo AdaptationVincent Pegoraro, Carson Brownlee, Peter S. Shirley, Steven G. Parker[paper] [slides] [bibtex] Abstract: This paper presents a novel method that effectively combines both control variates and importance sampling in a sequential Monte Carlo context while handling general single-bounce global illumination effects. The radiance estimates computed during the rendering process are cached in an adaptive per-pixel structure that defines dynamic predicate functions for both variance reduction techniques and guarantees well-behaved PDFs, yielding continually increasing efficiencies thanks to a marginal computational overhead. While remaining unbiased, the technique is effective within a single pass as both estimation and caching are done online, exploiting the coherency in illumination while being independent of the actual scene representation. The method is relatively easy to implement and to tune via a single parameter, and we demonstrate its practical benefits with important gains in convergence rate and applications to both off-line and progressive interactive rendering.
The Sponza Atrium illuminated by a directional light with 1-bounce global illumination, the Conference Room shaded with ambient occlusion, David with a Phong BRDF illuminated by the Grace Cathedral environment map, and the Sibenik Cathedral during a progressive interactive session. |
