3Delight for Maya lets you run MEL scripts before and after each shadow map is rendered. These two variables are automatically defined in the context of the MEL script:
string $shape_path → Contains the current light shape path.
string $attribs_node → Contains the current light attribute node name.
Pre Render MEL
Specifies a MEL script that will be executed before the shadow map is rendered. More precisely, the script will be executed just before the FrameBegin RIB statement of the shadow map. This attribute is empty by default.
Post Render MEL
Specifies a MEL script that will be executed after the shadow map is rendered. More precisely, the script will be executed just after the FrameEnd RIB statement of the shadow map. This attribute is empty by default.