Test Studio lighting with Maya mentalRay

Tip: 

Mental Ray use shade MIP 

edit the "mentalrayCustomNodeClass.mel", by default it look like this 

search in X:\Autodesk\Maya20xx\scripts\others

// Internal MentalRay Nodes. Not meant to be used with Maya.
  int $enableMIPShaders = (`optionVar -query "MIP_SHD_EXPOSE"`== 1);


replace the value 1 by 0 like this one and save it