Accelerating Frustum Traced Shadows Using Conservative Shadow Maps

Abstract

This paper proposes a pipeline to accelerate the computation of frustum traced hard shadows. Recently this shadow algorithm has been applied to real-time applications such as video games, but it is computationally expensive compared to shadow mapping. To reduce the computation cost of the frustum tracing, this paper employs a two-pass visibility test by integrating a conservative shadow map into the pipeline of frustum traced shadows. Furthermore, this paper also presents a more precise implementation of the conservative shadow map than the previous method. In our experiments for 4K screen resolution, although the performance improvement varies depending on the scene, the shadow computation time is improved by about 2.4 times on average.