To Add a Hole to a Slab/Roof Slab

Use this procedure to add a hole to a slab or roof slab.

The hole adds new vertices and edges, which you can edit as you do other slab or roof slab vertices and edges.

You can use polylines or three-dimensional (3D) objects, such as walls and mass elements, to create the hole.

• Holes generated by a closed polyline are projected from the polyline to the slab or roof slab, using the current user coordinate system (UCS).
• 3D objects must intersect the slab or roof slab without any projection.

If the objects contain an interior void, you are prompted to use the inside or outside surface to create the hole. For example, if you create a chimney using four wall objects, you can cut the hole at the inside or outside of the chimney. The new hole faces are aligned with the surfaces of the cutting bodies, and are not necessarily parallel to each other.

The smoothness (tessellation) of curved edges is controlled by 2 AEC display resolution settings called Facet Deviation and Facet Maximum. Beginning with Autodesk Architectural Desktop 2007, you can adjust these settings after the slab or roof slab is created. Also, the individual segments or facets making up a curved edge are no longer treated as separate edges; each arc on the perimeter of a slab or roof slab is treated as a single edge.

Adding a hole to a slab

Adding a hole to a roof slab

1. Draw a closed polyline in the shape and location for the hole, or add an object in the location for the hole.
2. Select the slab or roof slab.

   If the object selected is…	Then…
   a slab	click Slab tabModify panelHole drop-downAdd.
   a roof slab	click Roof Slab tabModify panelHole drop-downAdd.

3. Select the closed polyline or the connected objects that define the hole, and press ENTER.
4. Enter n (No) to keep the geometry, or enter y (Yes) to erase the geometry.
5. If you select 3D objects, you are prompted to create the hole at the inside or outside surface of the cutting objects. Press Enter to use the outside of the object to define the hole, or enter i (Inside) to use the inside or void of the object to define the hole. This prompt is displayed even if the bodies do not contain an inner void, in which case the Inside option does not create a hole.
Note: If you create a hole that is outside or which overlaps the slab or roof slab baseline or perimeter line at an overhang, the body of the slab or roof slab is cut, but the fascia and soffit remain. In this case, it is better to create a hole by cutting the slab or roof slab.