anchor.diff:  
   It states that at a micro level a surface is not plane, but formed of a multitude of little randomly aligned surfaces, the microfacets. Those surfaces acts as small mirrors that reflects incoming light. The idea behind this BRDF is that only some of those facets may be oriented so that the incoming light reflects to your eye. The smoother the surface, the more all facets are aligned, and the most neat is the light reflection. In the contrary, if a surface is rough, the facets are more randomly oriented so the light reflection is scattered on the surface, and the reflection looks more blurry.
   
  -image::Specular.png[Specular,width="320",height="250",align="center"]
  +image::jme3/advanced/DiffuseLambert.jpg[Specular,width="320",height="250",align="center"]
   Microfacet specular factor for a direct light source. On the left a smooth surface, on the right a rough one. Note how the reflection is scattered on the surface when it’s rough.
   
   The microfacet BRDF we use is called Cook-Torrance. From my readings, I couldn’t find any implementation that use another specular BRDF. It seems like this is the global form of any microfacet BRDF.
  
positive.code: *Fresnel factor called F*. Discovered by Augustin Fresnel (frenchies are sooo clever), it describes how light reflects and refracts at the intersection of two different media (most often in computer graphics : Air and the shaded surface)
  
  *Geometry shadowing term G*. Defines the shadowing from the micro facets
  
negative.code: 
  The most used diffuse BRDF in games. It’s very popular because it’s very cheap to compute and gives good results. This is the most simple way of computing diffuse.  link:https://en.wikipedia.org/wiki/Lambertian_reflectance[here are the details]
  
  image::jme3/advanced/DiffuseLambert.jpg[DiffuseLambert,width="320",height="250",align="center"]
  Diffuse Lambert factor for a direct light source (directional light) with a yellow surface color.
  
  Some Alternatives :
  