http://www.marmoset.co/toolbag/learn/materials
http://digitalerr0r.wordpress.com/2009/03/26/xna-shader-programming-tutorial-8-gloss-map/
对specularmap sample = speSampVal
对glossmap sample = glossSampVal
specularResult = speSampVal * (speFactor)glossSampVal
specularmap控制光照的颜色强度
glossmap控制反光的范围，决定材质质感