A pass contribution map associates a subset of the lights and renderable objects in the scene to one or more render passes. When rendering a given render layer, only the pass contribution maps linked to the layer are applied.
Render passes that are not connected to any objects through pass contribution maps are implicitly associated to all objects.
Pass Contribution Map Options Active Enable this attribute to use the pass contribution map.
Open Render Settings Click this button to open the Render Settings window.