If you plan to borrow Maya using this universal method that works with most Autodesk products: About Maya > Product Information > Borrow License, you will notice that you will not be able to render a file using mental ray.
Believe it or not, the instructions to get mental ray to work is in the documentation. The reason for this odd behavior is because mental ray is a ‘sub feature’ of Maya.
If you are using Maya and you plan to borrow a license and require mental ray, please review the following steps here and click on:
The abridged instructions for borrowing a license for Maya on Windows is below:
1. Download NLM from www.autodesk.com/nlm-ipv4-windows and install it on client computer that you want to borrow Maya on.
2. Run the LMTOOLS utility on the client computer.
3. Open the LMTOOLS utility by selecting Start > Programs > Autodesk > Common Utilities > FlexLM License Utilities.
4. In the LMTOOLS utility, switch to the Borrowing tab.
In the Vendor Name field, enter adskflex
Enter the Return Date
Enter Return Time
Click Set Borrow Expiration
5. Launch Maya.
6. Create a poly sphere and add a directional light and render it using mental ray.
7. If you are still connected to your license server. This automatically borrows a license for that sub-feature.
8. Click on the Don’t Borrow Any Today when your are done or you will continue to borrow other Autodesk products on your computer that your license server is issuing. This will only happen if you launch the product. i.e. Softimage, MotionBuilder, Mudbox.
Thanks to Ming Mah for demoing this workflow to the support team.