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.
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.
How are elements drawn with respect to the view range?
- Elements within the boundaries of the primary range that are not cut are drawn in the element’s projection line style.
- Elements that are cut are drawn in the element’s cut line style.
- Elements that are within the view depth are drawn in the beyond line style.
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.
Additional View Range Rules
- Elements that are strictly below the cut plane, but are at least partially within the view range, are shown as viewed from above. Components display according to Family Element Visibility Settings for Plan/RCP. See Managing Family Visibility and Detail Level.
- Walls shorter than 6 feet (or 2m when working in metric units) are not cut, even if they intersect the cut plane.
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.
- There are a few categories for which an element located above the cut plane but partially below the top clip is shown in plan. These categories include windows, casework, and generic models. These objects are shown as viewed from above.
- Model elements located outside of the view range generally are not shown in the view. The exceptions are floors, stairs, ramps, and components that stay or are mounted on the floor (like furniture). These are shown even when slightly below the view range.
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.
- Visibility in reflected ceiling plan (RCP) views is similar to plan views with the exception that objects are presented as viewed from below and mirrored.