Edit Bar controls: none
This tool can be used to indicate a region of the 3D scene and enlarge it to fill the window.
Pick one corner of the region you require by clicking the left mouse button - it does not matter which corner you choose. As you hold down the left mouse button and move the mouse, a flexible box is displayed indicating the region. Pick the opposite corner of the required region.
Your view zooms into the chosen region.
Related topics: Notes On 3D Tools.