Changes

[[Image:wire_pic1.png|thumb|350px|EM.Libera's Navigation Tree.]] All the objects in your project workspace are organized into object groups based on their material composition and geometry type in the "Physical Structure" section of the navigation tree. In EM.Libera, you can create three different types of objects (click on each type to learn more about it):

Both of EM.Libera features 's two different simulation engines: , Wire MoM and Surface MoM. Both simulation engines , can handle metallic structures. The Wire MoM engine models metallic objects as perfect electric conductor (PEC) wireframe structures, while the Surface MoM engine treats them as PEC surfaces. The PEC objects can be lines, curves, surfaces or solids. All the PEC objects are created You define wires under the '''PECThin Wire''' node in the '''Physical Structure''' section of the Navigation Tree. Objects are grouped together by their color. You can insert different PEC groups with different colors. A new PEC group can be defined by simply right clicking on the '''PEC''' item in the Navigation Tree and selecting surface and volumetric metal objects under '''Insert New PEC...Objects''' from the contextual menu. A dialog for setting up the PEC properties opens up. From this dialog In other words, you can change the name of the group or its color. In EM.Liberadraw lines, PEC objects have an additional property, which is '''Wire Radius''' expressed in project units. This parameter is used in conjunction with Pocklington's integral equation for wire objects only. The line polylines and other [[Curve Objects|curve objects]] you draw as thin wires, which have a radius [[parameters]] expressed in the project workspace are not displayed as cylinders with the specified radiusunits. Of EM.Libera's two simulation engines, only the Surface MoM solver All types of solid and surface CAD objects can handle dielectric objectsbe drawn in a PEC group. Dielectric Only solid CAD objects are created can be drawn under the '''DielectricObjects''' node in the '''Physical Structure''' section of the Navigation Tree. They are grouped together by their color and material properties. You can insert different dielectric groups with different colors and different permittivity e_r and electric conductivity s. Note that a PEC object is the limiting cases of a lossy dielectric material when σ → ∞. {{Note|Under dielectric material groups, you cannot draw surface or curve CAD objects.}}