Trying to make a hole in an extrusion converted to Roof Slab
Accepted solution
I was not able to get a Hole to work in a Roof Slab created from an extruded Mass Element. But I was able to cut an opening using a Mass Element as either a subtractive Body Modifier or a subtractive Interference. The following images were taken from the attached example file, done in AutoCAD Architecture 2020.
Here is an image showing the Polyline, the Mass Element that was extruded from that Polyline, and the Roof Slab that was created by converting (a copy of) that Mass Element. The converted Roof Slab has a Body Modifier applied to achieve that shape (Body Modifier "(0)"). The two Mass Elements that were used to add the subtractive Body Modifier and subtractive Interference to the Roof Slab are also visible here.
In the image below, layer G-Mass-Intf, on which the two Mass Elements used to cut the Roof Slab are placed, is frozen, revealing the openings.
Here are the Body Modifier and Interference worksheets, with the ones doing the cutting highlighted:
As for which to use, it depends on what works better for you. You can edit, move or delete the Mass Element used to create the Body Modifier, and the Body Modifier will remain as it was when originally created. If you do the same with the Mass Element used to create the Interference condition, the opening will be modified as well. (If you move the Mass Element completely outside of the Roof Slab or delete it, there will be no opening.)
If you can get the Mass Element/opening correct up front, will not need to change it and do not want to manage the Mass Element used to create it in the future, then a Body Modifier would be the way to go. If you want to be able to make edits to the opening in the future by editing the Mass Element, then the Interference condition may be the better choice.