Use section boxes to clip the viewable portion of a 3D view.
You can use a section box to clip the viewable portion of a 3D view. When you enable a section box in a 3D view, the only change to the view is the addition of the section box. The following image shows a 3D view with a section box enabled.
After you enable the section box, you can modify its extents using drag controls in the 3D view, or you can modify extents from other views, for example a plan or elevation view. Section box extents are not cropped by the view’s crop region.
To enable a section box
The following image shows the section box selected with the blue arrow drag controls visible. The section box extents have been modified to cut into the stair tower.
To modify section box extents outside of the 3D view
To control visibility of section box extents
As an alternative, to hide the section box, right-click it and select Hide in ViewElements.