https://developer.nvidia.com/gpugems/gpugems3/part-ii-light-and-shadows/chapter-10-parallel-split-shadow-maps-programmable-gpus
shadow mapping (Williams 1978) has been used extensively in 3D games and applications for producing shadowing effects. however, shadow mapping has inherent aliasing problems, so using standard shadow mapping is not enough to produce high-quality shadow rendering in complex and large scenes. in this chapter we present an advanced shadow-mapping technique that produces antialiased and real-time shadows for large-scale environments. we also show the implementation details of our technique on modern programmable GPUs.
10.1 Introduction
the technique we present is called parallel-split shadow maps (PSSMs) (Zhang et al. 2007 and Zhang et al. 2006). In this technique the view frustum is split into multiple depth layers using clip planes parallel to the view plane, and an independent shadow map is rendered for each layer, as shown in Figure 10-1.
Figure 10-1 Parallel-Split Shadow Maps in
the split scheme is motivated by the observation that points at different distances from the viewer need different shadow-map sampling densities. by splitting the view frustum into parts, we allow each shadow map to sample a smaller area, so that the sampling frequency in texture space is increased. with a better matching of sampling frequencies in view space and texture space, shadow aliasing errors are significantly reduced.
来源：CSDN
作者：wodownload2
链接：https://blog.csdn.net/wodownload2/article/details/103778018