This option allows the user to modify a previously defined Material. When the Materials –Edit option is selected the Edit Material window (following Figure) appears. When the material to be edited has been selected in the Select material combo box, its color can be modified. It is important to remark that the properties of the materials may be modified, but not their type (defined by geometry, defined by electrical impedance, or defined by reflection coefficient). To edit the material parameters, click on the Set Parameters button and the corresponding window (following Figure) will appear. The rest of the editing process may continue as explained in section Add.

Figure 1. Edit Material panel