Many advanced tools require a previous selection. Selections are created vie the following functions and are saved as described in chapter Saving Selections:

Individual parts of an assembly can be selected by clicking them directly within the model area or by clicking the corresponding entry in the model structure for more processing steps.

The selection can be cancelled by pressing the [Esc] key or by clicking in the background of the model area.

With [Ctrl] pressed at the same time, more geometries can be added to the selection. Clicking the selected geometries again will deselect them.

With the [ñ] key pressed at the same time in the model structure, all parts can be selected which are grouped in the structure between the first and the last selected entry.

Clicking an object will initially select the relevant geometry (lowest level in the Structure view). A further click of a previously selected object selects the next higher level of the structure, and so on until the entire model is selected. Another click will then return the selection to the initial geometric element. This enhanced selection can be disabled via Settings > Scene > General.

You can also choose a Selection frame via Start > Controls. It can be used by dragging a pane with the left mouse button pressed. The content inside the frame will then be selected.

Please note that all geometries that at least partially lie within the selection frame are selected when the frame is drawn from left to right. Dragging the pane from right to left on the other hand, will only select geometries completely contained within the frame.

All visible geometries can be selected by clicking the [Select all] button or by using the shortcut [Ctrl]+[A] in the Selections area.

You will find a description of other options for creating specific selections in ch. Filter (Search).