//Select by material: do_Sel_by_mat v1.0 December 1, 2009
1. Description - This script selects all the faces on a poly mesh that share the same material. Usefull on large models that have many materials. Despite the Maya's default "Select Objects with Material" from Hypershade this script selects the faces from the curent object only.
a) copy "do_Sel_by_mat.mel" to your Maya's scripts directory (Example: "C:\...\Documents\maya\version\scripts").
b) Start Maya. If you have it already open type "rehash" in the command window and execute.
c) the script should be sourced now ...
If it isn't then u can manualy source it from the Script Editor (Window--> General Editors --> Script Editor).
3. How it works - All you have to do is to select one face on your desired poly mesh and run "do_Sel_by_mat()".
4. Issues - The script will work only on meshes wich have at least 2 shaders/mats (I assume you know to select all :P) and only 1 selected face.
This script may be freely distributed. Use/Modify at your own risk!
Special thanks to Ken Proudfoot and Ben Wronsky for their Get_mat and materialSelect scripts.