I am trying to extract some GIS data from an IFC file containing manholes, pipes and ducts. The IFC file have some small gaps at bends, like this:

I’m extracting the top facing faces in the IFC and simplify to one polygon per IFC element. I still get these small gaps in my GIS data:

I have tested the Generalizer with a lot of different algorithms and settings, but those that seem to be able to remove these (like the Wang algorithm) removes my Z values…
Is there a way to simplify or smoothen the data to remove these while retaining the 3D area boundaries?

