Question

IfcOpeningElement does not cut/subtract windows in IfcWall.


I'm trying to import different IFC modells via IFC Reader and for some it happens that the walls do not contain the respective openings where the windows are (see Screenshots of BIM Viewer and FME Inspector. I tried different import settings, and thought especially "Subtract Opening Geometries" should solve the problem but it still didn't work. I'm having a hard time finding a solution as I'm not entirely sure how FME cuts out these openings.

 

Any suggestions what might casue the problem?


2 replies

Userlevel 3
Badge +13

Hello @michafranz​, sorry you encountered this! There are two things I can suggest. It might be that the Width of Opening is slightly smaller than Wall, so Opening is there, but it doesn’t extend all the way up to surface. To check this, you can use a GeometryColorSetter to set to color with Alpha set 25% - this will allow you to see through walls to see any voids created by the Openings. Otherwise, it would be good to ensure Openings are properly linked to parent Walls. Best, Kailin.

Hi @kailinatsafe​ Thanks for the hint with the GeometryColorSetter, using that I saw that the Width of the Opening is actually large enough. I also checked the links to the parent walls and the parentID of the Openings and the uniqueID of the wall are the same. However I could solve the problem with a workaround, by importing a BoundaryRepresentation (BREP) version of the same IFC modell.

Would still be interesting to know what could've caused the problem..

 

Thanks anyway!

Reply