RTSDF: Real-time Signed Distance Fields for Soft Shadow Approximation in Games

Abstract: Signed distance fields (SDFs) are a form of surface representation widely used in computer graphics, having applications in rendering, collision detection and modelling. In interactive media such as games, high-resolution SDFs are commonly produced offline and subsequently loaded into the application, representing rigid meshes only. This work develops a novel technique that combines jump flooding and ray tracing to generate approximate SDFs in real-time. Our approach can produce relatively accurate scene representation for rendering soft shadows while maintaining interactive frame rates. We extend our previous work with details on the design and implementation as well as visual quality and performance evaluation of the technique.