Staircase

The Staircase is an interior scene that is relatively simple to render with traditional path tracing. Path guiding mainly helps in the indirectly-lit regions below the staircase and on the door frame. Our radiance-driven neural path guiding (NPG-Radiance) performs best among the radiance-driven approaches at equal sample counts. Only marginal further benefit is obtained when also incorporating the product (NPG-Product), because the scene consists mostly of diffuse materials. Primary-sample-space path-sampling techniques also offer an improvement over unidirectional path tracing, albeit a smaller one than path-guiding approaches. Our NPS slightly outperforms PSSPS [Guo et al. 2018] with an equal number of samples.