Veach Door

The classic Veach Door scene was originally made to challenge the efficiency of all rendering algorithms but metropolis light transport. Only a small fraction of the light in the other room passes through the opening in the slightly ajar door. In this scene, our radiance-driven neural path guiding (NPG-Radiance) is better at finding paths through the door opening than the competing technique by Müller et al. [2017] and is further outperformed - especially on the metal teapot - by incorporating the product (NPG-Product). Primary-sample-space path-sampling techniques offer little to no benefit over unidirectional path tracing with our NPS slightly outperforming PSSPG [Guo et al. 2018].