Who would have thought that 3D Studio Max could give a bit more…
There are some “Production” Shaders that add more flexibility and opportunity for the Mental Ray renderer.
Have I got your attention? 
Go to your 3dsmax\2008\mentalray\shaders_standard\include\production_mx.mi and open this file using a simple text editor.
Next go through this file and find every copy of the word “hidden” except the first in the code which is a global variable and change it to # “hidden” which will comment out and unleash the extra shaders.
Simply restart max and activate Mental Ray as your renderer and check out the many new options in the material editor 
Your Welcome!!!!! ENJOY …....

