The physical model objects that are currently selected in the view window are referred to as the selection set. STAAD.Pro Physical Modeler has a variety of methods for you to select the precise portion so the model to add to the selection set. The user interface also respond dynamically to the current selection set.
To select any model object, simply click on that object with the left mouse button (hereafter just referred to as a "click").
Select By Tools
You can right-click to display the pop-up menu anywhere in the view window. The top portion of this menu contains a number of quick selection tools that allow you to select all objects, invert your selection, select by object description, or by object type filtering.
You can select objects by clicking and dragging the mouse pointer to make a rectangular area in the view window (hereafter referred to as a "fence selection"). When you start the fence on the left and drag to the right, only those objects contained entirely within the fence are selected. However, when you start the fence on the right and drag to the left, any object within or crossing the fence boundary will be selected.