Apply a section box to limit the geometry shown in a view.
This video demonstrates the following:
You can apply a section box to a 3D view to limit the geometry shown in the view. The edges of the section box are cutting edges, so element geometry intersected by the section box will display using the Cut object style for the element. To display the section box, in the Properties palette for a 3D view, select Section Box. When a section box is first displayed, the extents of the visible geometry are used to define the extents of the section box. Select the section box and use the grip controls to resize the extents. Right-click and select to hide the section box so it is no longer visible in the view.
In some cases, such as working in a perspective view, it can help to use the ViewCube to navigate the view to a direction where the section box is more easily adjusted, and then navigate back to the original view direction. A section box can also be applied to a selection set. Select elements in the view, and then on the Modify tab, click Selection Box. The elements in the extension define the extents of the section box.
The selection box tool can be used in 2D view. When used in a 2D view, the section box is applied to the default 3D view of the project. If there is no default 3D view, one is created.
Use a section box in your views to isolate geometry, to help you work in the view, or to present your projects.