The "Add" option of the materials menu allows the user to add a new material to the list of materials. When this option is selected, the following tab will appear:
"Add Material" tab
In this tab, the user can set the parameters for the material they want to create. The "Material Attributes - Name" option allows the user to give a name for the created material for future reference, and the "Material Attributes - Color" allows to give the material a representative color by clicking the small rectangle with the current material color (white, by default). On more details about color selection for a material, consult "Appendix A: Color selection".
The user should modify the Epsilon (permittivity) and Mu (permeability) values associated with the material, specifying their real parts (on the left text field) and imaginary parts (on the right text field), or the loss tangent and relative permittivity values. Common real parts for these values are greater or equal to "1.0". Additionally, materials with positive imaginary parts are considered to have gains, while materials with negative imaginary parts are considered to have losses.
When the user is satisfied with the properties given to the material, they should click the "Save" button to confirm the creation of the material.