To open the Lightmapping Settings, go to Window > Rendering >Lighting Settings, and navigate to Lightmapping Settings.
|Lightmapper||Use this to specify which internal lighting calculation software to use to calculate lightmaps in the Scene. The options are:
The default value is Progressive CPU.
Lightmapping Settings are specific to the Lightmapper backend. To see the settings information for each lighting system, see the documentation on the Progressive CPU Lightmapper, the Progressive GPU Lightmapper, and Enlighten.