Geometry problem with Revit IFC-file

[GVladislavG]

Hello, team!

I have a problem with geometry generation in Revit IFC-file

BimVision geometry

Geometry by xBim

Problem file is attached.
RevitTest.zip

[andyward]

Have reproduced in both WebUI and WindowsUI. Will need deeper investigation. The model validates fine, although technically IfcFaceBasedSurfaceModel is deprecated in IFC4 (i.e. it should be FacetedBrep)

Highlighted the rogue mesh and it's likely origin

I'd guess there's some edge case we're not handling (possibly in our XbimTessellator) but will need someone to dig in.