Material Editor > Maps rollout > Click a Map button. > Material/Map Browser > Pick a shader with “(lume)” in its name.

Note: Shaders appear in the Browser only if the mental ray renderer is the currently active renderer.

The LumeTools Collection of shaders provide a variety of naturalistic effects when used with the mental ray renderer. In the Material/Map Browser, the name of these shaders is followed by “(lume).” These are the lume shaders provided with 3ds Max:

Note: You can also access the lume shader help by choosing Help > Additional Help, highlighting Lume Tools in the list, and then clicking Display Help.