Step1:Get "Slidenormals Thief" maxscript.
Run the script and set up a UI shortcut from "customize user interface" if you want (its found under "Category: Slidetools").
Then select your object and add a "edit normals" modifier. Create a sphere or half-sphere (depending on how you want your lighting to be affected) and shape it over your plane cluster. Add an "edit normals" modifier to that too.