EM.Illumina organizes physical objects by their surface type. Any object in EM.Illumina is assumed to be made of one of the three surface types:
# '''[[Defining_Materials_in_EM.Cube#Perfect_Electric_Conductors_.26_Metal_Traces | Perfect Electric Conductor (PEC)Surface]]'''# '''[[Defining_Materials_in_EM.Cube#Perfect_Magnetic_Conductors_.26_Slot_Traces | Perfect Magnetic Conductor (PMC)Surface]]'''
# '''[[Defining_Materials_in_EM.Cube#Impedance_Surfaces_.26_Conductive_Sheet_Traces | Generalized Impedance Surface]]'''