To select all items in a polygonal region on a photograph or in the 3D Viewer, use the “Region Select (Temporary) tool” (ribbon toolbar’s View Tab or "D" short-cut key). When in this mode click the left mouse button anywhere in the photograph to begin. Then move the mouse to the next vertex of the polygonal area and click again. You will see a "rubber-band" line to guide you. Repeat this to surround the objects to be selected. Click within ten pixels of the starting point, or double click anywhere in the photo and the region will close and the objects will be selected. Hitting the ESC key during the region definition will cancel it. This mode is a ‘temporary’ one in the previous mode is activated as soon as the region is closed. This mode also works in the 3D Viewer.
Lines and Surfaces must be completely within the polygonal region to be selected. Multiple select also works with region selection in that you can add to any current selection by holding the shift key while drawing a new region.