The White Room is a typical interior scene with a mix of textured glossy and diffuse materials that is easy to render for a unidirectional path tracer due to large light sources; the windows are actually diffuse area emitters. Since most light transport is governed by diffuse materials, radiance-based guiding techniques generally improve over unidirectional path tracing. Noise is further reduced on glossy materials, such as the television and the reflections on the floor, by using product-driven path guiding (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].