3D models are analyzed with MS3p and 2D models are analyzed with MS2p. In either case there should be one contiguous simulation domain that contains all of the structures in the system. In MS3p the simulation domain may be located anywhere in 3D space, and in MS2p it should be in the x-y plane, above the x-axis.
Every MS2p or MS3p simulation must contain at least one source, and it may contain as many sources as the system requires. The sources can be either coils or permanent magnets, or a combination of the two, depending on the system that is being modeled.