Light space cascaded shadow maps for large scale dynamic environments

Abstract

Cascaded shadow maps (CSMs) is an efficient real-time shadow rendering method for large scale dynamic environments. When view direction and light direction are not perpendicular, CSMs unnecessarily render objects to different shadow map textures. This paper presents the light space cascaded shadow maps (LiSCSMs) algorithm to solve CSMs' redundant rendering problem. We propose a light space scene splitting scheme which divides the scene into non-intersecting layers in light space, and a fast shadow map rendering method with irregular frustum clipping and scene organization to generate a shadow map for each layer, ensuring that any shadow sample point never appears in multiple shadow maps. Finally, a succinct shadow determination method is given to produce higher quality shadows when rendering scene. The results show that LiSCSMs effectively improves the efficiency and shadow quality of CSMs by avoiding redundant rendering, and can produce high-quality shadow rendering in large scale dynamic environments with real-time performance. © Springer-Verlag 2009.