"The Reyes Image Rendering Architecture" Robert Cook. 1987 http://excelsior.biosci.ohio-state.edu/~carlson/history/PDFs/cook-reyes.pdf "Advanced RenderMan 2: To RI INFINITY and Beyond" SIGGRAPH 2000 http://www.renderman.org/RMR/Publication…

http://psgraphics.blogspot.jp/2014/08/purity-in-rgb.html

https://www.shadertoy.com/view/XsjXR1

http://www.slideshare.net/jrouwe/killzone-shadow-fall-threading-the-entity-update-on-ps4

http://slehar.wordpress.com/2014/03/18/clifford-algebra-a-visual-introduction/

http://www.slideshare.net/RenaldasZioma/unite2014-mastering-physically-based-shading-in-unity-5

https://docs.google.com/file/d/0B11iL4IgOgWLaXpweVJxUmFvNkk/edit