ReSTIR BDPT: Bidirectional ReSTIR Path Tracing with Caustics

Recent spatiotemporal resampling algorithms (ReSTIR) accelerate real-time path tracing by reusing samples between pixels and frames. However, existing methods are limited by the sampling quality of path tracing, making them inefficient for scenes with caustics and hard-to-reach lights. We develop a ReSTIR variant incorporating bidirectional path tracing that significantly improves the sampling quality in these scenes. Combining bidirectional path tracing and ReSTIR introduces multiple...