This script was written for a friend who had a scene with 150 textures and wanted to add Utility Gamma & Gain(MI) for every diffuse texture. Thought this might be useful for MentalRay users out there.

Features:
– Adds Mental ray Gamma and gain utility to the diffuse map channel, only if a bitmap texture exists.
– Currently adds only for Arch and Design,Standard Material and Multi Material in the diffuse map channel.

Download Link:
http://www.scriptspot.com/3ds-max/mentalray-utility-gamma-adder