影子

Dynamic Shadow Projector - Tutorial

http://nyahoon.com/products/dynamic-shadow-projector/tutorial

利用Projector实现动态阴影

http://www.tuicool.com/articles/BRNzEve

ScreenSpaceShadowMask Blur推荐

http://blog.uwa4d.com/archives/ScreenSpaceShadowMaskBlur.html