Area ReSTIR: Resampling for Real-Time Defocus and Antialiasing
Song Zhang*, Daqi Lin*, Markus Kettunen, Cem Yuksel, and Chris Wyman
ACM Transactions on Graphics (Proceedings of SIGGRAPH 2024), 2024
Recent advancements in spatiotemporal reservoir resampling (ReSTIR) leverage sample reuse from neighbors to efficiently evaluate the path integral. Like rasterization, ReSTIR methods implicitly assume a pinhole camera and evaluate the light arriving at a pixel through a single predetermined subpixel location at a time (e.g., the pixel center). This prevents efficient path reuse in and near pixels with high-frequency details.We introduce Area ReSTIR, extending ReSTIR reservoirs to also integrate each pixel’s 4D ray space, including 2D areas on the film and lens. We design novel subpixel-tracking temporal reuse and shift mappings that maximize resampling quality in such regions. This robustifies ReSTIR against high-frequency content, letting us importance sample subpixel and lens coordinates and efficiently render antialiasing and depth of field.
