As the title of the script telling all, no need extra notes, right? I wrote this script by user request at ScriptSpot forum. More details and the script you can find there.
But... OK, here is a few notes anyway.
It's a macro script that select all faces with Mareial ID equal to selected one. Work with base objects converted to Editable Poly or Mesh, plus with 4 modifiers (Edit Mesh, Mesh Select, Edit Poly, Poly Select). Work on currently selected object/modifier in the modifier stack (which make it usage very flexible).
Well, need some warning notes about Edit Poly Modifier.
Yeah, a very powerful modifier but with unstable scripting control.
The rest 3 modifiers involved here works fine and stable, but you can end with incorrect result when using Edit Poly modifier, and this not come from the script code but from the unstable nature of EditPolyMod interface. Sorry to tell that but this cannot be fixed with scripting code.
Possible "Plan B" could be to add new modifier on top (as Poly Select for instance), but this is very dirty solution. As we need stable and working code in production as more sensibly would be to replace "naughty mod" with other modifiers (like Edit Mesh for instance).
This is another script which reminded me why I not trust to this modifier and why I do not use it anymore in my scripts. So you're warned, and I can't do anything more than this for you, right?
However, I hope you appreciate my efforts and all the comforts that come from this macros.