那么，什么是基于物理的着色呢？网上有大量相关介绍可以帮助你快速了解：
http://www.marmoset.co/toolbag/learn/pbr-theory
http://www.marmoset.co/toolbag/learn/pbr-practice
http://filmicgames.com/archives/547
http://filmicgames.com/archives/557
http://www.fxguide.com/featured/game-environments-parta-remember-me-rendering/
http://seblagarde.wordpress.com/
http://renderwonk.com/publications/s2010-shading-course/
http://http.developer.nvidia.com/GPUGems3/gpugems3_ch24.html