The objects that you draw in EM.Cube's project workspace always belong to the "Active" surface group. By default, the last object group that you created remains active until you change it. The current active group is always listed in bold letters in the Navigation Tree. Any surface group can be made active by right clicking on its name in the Navigation Tree and selecting the '''Activate''' item of the contextual menu. If you start a new [[PO Module]] project and draw any object without having previously defined a surface group, a default PEC group is automatically created and added to the Navigation Tree to hold your new object.
You can move one or more selected objects to any material group. Right click on the highlighted selection and select '''Move To > Physical Optics >''' from the contextual menu. This opens another sub-menu with a list of all the available surface groups already defined in [[PO Module]]. Select the desired surface group, and all the selected objects will move to that group. The objects can be selected either in the project workspace, or their names can be selected from the Navigation Tree. In the latter case, make sure that you hold the keyboard's '''Shift Key''' or '''Ctrl Key''' down while selecting a material group's name from the contextual menu. You can also move one or more objects from a PO surface group to EM.Cube's other modules, or vice versa. In that case, the sub-menus of the '''Move To >''' item of the contextual menu will indicate all the EM.Cube modules that have valid groups for transfer of the selected objects. ''' {{Note that in |In EM.Cube, you can import external CAD models (such as STEP, IGES, STL models, etc.) only to [[CubeCAD]]. From [[CubeCAD]], you can then move the imported objects to any other computational module including [[PO Module]]. '''}}
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