Sorry for not getting back to you on this. Had thee hectic 20 hour days at the office solving a problem with one of our systems.

Thanks Gen for answering.

Looking for the attributes of this node:

Can you show us the attributes of your layered texture? Also, what file format are you using for the grass?

To which attributes of the material did you connect the dirt and grass file nodes?

Hi Constantine. Are you using painFX for the grass? If so, paintFX does not work with mental ray. You need to convert it to polygons first. (Under the Modify -> Convert menu option)
For the...