anchor.diff:  Unfortunately we can’t take each pixel of the env map and compute light as if it was a direct light source and hope for the best.
   
   There’s crazy math around that topic, and to be honest I ddidn’tget all of it myself. So instead of explaining difficult math equations that may be confusing, I’m gonna go straight to the point : How are we going to compute lighting from the environment map?
  +
   === IBL Diffuse
   
   First we need to compute Diffuse factor from the environment map. Remember our diffuse BRDF from last post? *Lambert*.
  
positive.code: 
  A picture worth thousand words
  
  image::jme3/advanced/Cube_mapped_reflection_example.jpg[Cube_mapped_reflection_example.jpg,with="320",height="250",align="center"]
  from wikipedia : TopherTH at the English language Wikipedia [GFDL (http://www.gnu.org/copyleft/fdl.html), GFDL (http://www.gnu.org/copyleft/fdl.html) or CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0/)], via Wikimedia Commons Here the reflected Ray is our reflection vector.
  
  Here the reflected Ray is our reflection vector.
  
negative.code: 
  With this technique I can compute a 128X128 irradiance cube map on the CPU in Java in about 200ms. Too slow to be done on each frame, but at design time that’s the blink of an eye.
  
  image::DiffuseIBL.png[DiffuseIBL,with="320",height="250",align="center"]
  Here is the diffuse effect of indirect lighting using an irradiance cube map
  
  === IBL Specular
  