Every plan view has a property called View Range, also known as a visible range. The view range is a set of horizontal planes that control object visibility and display in the view. The horizontal planes are Top, Cut Plane, and Bottom. The top and bottom clip planes represent the topmost and bottommost portion of the view range. The cut plane is a plane that determines at what height certain elements in the view are shown cut. These 3 planes define the primary range of the view range.
View depth is an additional plane outside of the primary range. You can set the level of view depth to show elements below the bottom clip plane.
By default, the view depth is coincident with the bottom.
The following image shows the view range of a plan view from an elevation view standpoint: Top, Cut plane, Bottom, Offset, Primary Range, and View Depth.
The following image shows the actual plan view for this view range.
Elements outside of the view range do not display in the view. The exception to this is if you set the view underlay to a level outside the view range. For more information on the Underlay view property, see View Properties.
To determine which elements can display as cut, see Managing Family Visibility and Detail Level.
You can change the display of cut and projection line styles through the Object Styles tool. You can change the display of the beyond line style through the Line Styles tool.
The 6 feet are measured from the top of the bounding box to the bottom of the primary view range. For example, if you create a wall with a sloped top face, when the top of the wall is 6 feet away from the bottom of the primary view range, the wall is cut at the cut plane. When the top of the wall is less than 6 feet, the entire wall shows as projection even where it intersects the cut plane. This behavior always occurs when the Top Constraint property for the wall is specified as Unconnected.
Fascia, gutters, and slab edges are shown when their bottoms are within a tolerance of the primary view range bottom.
Floors, structural floors, and foundation slabs located outside the view range use an adjusted range that is 4 feet (approximately 1.22 meters) below the bottom of the primary range. Floors are drawn with the Beyond line style if the floor exists within this adjusted range.