I have a part for a thermal study. It has a planar face that should have two different emissivity values. One emissivity should be assigned to an array of small spots, and the remaining area should be the other emissivity. I guess I should start with a sketch of the spots. There is a "split" tab in the "Radiation" dialog box, but I can't seem to get it to work. Is this possible? I suppose I could create plugs of material under the spots that are bonded to the rest, but I think this would be very time consuming to set up, especially given the large number of spots.