Theory to Practice: Generalized Minimum-Norm Perspective Shadow Maps for Anti-aliased Shadow Rendering in 3D Computer Games

Abstract

Shadow mapping has been extensively used for real-time shadow rendering in 3D computer games, though it suffers from the inherent aliasing problems due to its image-based nature. The aliasing errors in shadow mapping consist of perspective aliasing error and projection aliasing error. In this paper, we propose a novel shadow-map reparameterization to reduce perspective aliasing for varying viewer and/or light. This reparameterizing technique keeps the perspective aliasing distribution optimal in possible general cases. Our experiments have shown the enhanced shadow quality using our algorithm in dynamic scenes.