An improved non-orthogonal texture warping for better shadow rendering

Abstract

In interactive applications, shadows are traditionally rendered using the shadow mapping algorithm. The disadvantage of the algorithm is limited resolution of depth texture which may lead to aliasing artifacts on shadow edges. This paper introduces an improved depth texture warping with non-orthogonal grid that can be employed for all kinds of light sources. For instance, already known approaches for reducing aliasing artifacts are widely used in outdoor scenes with directional light sources but they are not directly applicable for point light sources. We show that the improved warping parameterization reduces the aliasing artifacts and we are able to present high quality shadows regardless of a light source or a camera position in the scene.