Real-time Reflections in Mafia III and Beyond
Specular reflection plays a major role in overall visuals. Many methods exist to compute indirect specular (reflection), however all of the currently used techniques have many issues with image stability, floating reflections, missing reflection anisotropy, etc. This session will share how we implemented a hybrid screen-space and cube-map array tracing for 'Mafia III'. This method combined importance sampling with large screen-space blur. It addressed floating reflections and image stability as SSR/CM blend was seamless but didn't produce proper material response and introduced leaking on high-roughness materials. This talk will present an improved version that eliminates the large screen-space blur with smart sample distribution, spatio-temporal filter, screen and CM pre-filtering. This method works well on whole roughness range and achieves full-res reflections in about 3 ms on PS4 at 1080p.