# Chapter 11. Shadow Map Antialiasing — Michael Bunnell & Fabio Pellacini

- Source: https://developer.nvidia.com/gpugems/gpugems/part-ii-lighting-and-shadows/chapter-11-shadow-map-antialiasing
- Note: add-only excerpt; images/code truncated.

## Summary (full chapter read)
Classic real-time PCF: cannot prefilter depth; average many depth compares. Simplified 4×4 texel kernel (not REYES stochastic micropolygon region). NVIDIA HW does 2×2 bilinear PCF free; expand to 4×4 via 16 compares. 4-sample dithered subset of the 16 (screen-dependent pattern) ≈ grayscale dither—similar quality, 4× fewer taps. Fixed kernel still helps under magnification because overlapping neighbor filters average. Ancestor of Gems2 Ch17 adaptive branching PCF.