Gregory Igehy

Dancing at hemisphere coordinate

Bent normals / Terrain shadows

Notes for bent normals

https://rendermansite.pixar.com/ca_twopointo_cms_data/images/15860_5881.gif

For terrain : "Generating Soft Shadows Using Occlusion Interval Maps" GPU Gems1

http://http.developer.nvidia.com/GPUGems/elementLinks/fig13-02.jpg