Problems importing IFC extruded geometry into Revit 2019 and 2020

[jjkaelin]

We are working on a computational design add-in that outputs IFC4 proxy elements in SPF format. During testing we are encountering problems with importing extruded geometries. To help locate this problem we put together 3 test files based on the Building Smart example data ‘extruded-solid.ifc’ from https://github.com/buildingSMART/IfcDoc/blob/master/IfcKit/examples/basic-geometric-shape/extruded-solid.ifc

Test files (attached):

test-extruded-polygon-solid.ifc.TXT test-extruded-circle-solid.ifc.TXT test-extruded-rectangle-solid.ifc.TXT

(note that .TXT has been appended to filenames for uploading) test-extruded-rectangle-solid.ifc test-extruded-circle-solid.ifc test-extruded-polygon-solid.ifc

We tested importing these data into Revit 2019.2 (IFC Importer 19.2.0.0) and Revit 2020.1 (IFC Importer 20.1.0.1) with the following result: Revit 2019 - Link IFC: all ok (no errors or warnings in logs) Revit 2019 - Open IFC:
rectangle and circle ok, polygon does not display (no errors or warnings in logs) Revit 2020 - Link and Open IFC: none display (no errors or warnings in logs).

When Open IFC does not display the IFC data, a Generic Family is created in Revit, but It is not possible to create an instance.

We are surprised that with Revit 2020 we are experiencing more problems with IFC than in Revit 2019.

As a further note:

• all data are correctly imported with Navisworks Manage 2020 rectangle and circle are correctly imported with Bim Vision 2.20,
• polygon is imported but rendered incorrectly with Bim Vision 2.20.

Has anyone had similar experience? Do others get the same results with their Revit installation? It is certainly a concern that these basic geometries do not import into Revit correctly and we would be grateful to hear whether others are encountering this problem.

[jjkaelin]

Update: with the following change in test-extruded-polygon-solid

1025= IFCTRIMMEDCURVE(#1022,(#1008),(#1007),.T.,.CARTESIAN.);

this data is properly imported by Revit 2019 Open IFC and by Bim Vision.

The problems that I am having are then solely with Revit 2020.

[dvrvb]

Hi,

Although I'm not really familiar with importing IFC in Revit, I tested your test-extruded-polygon-solid.ifc and test-extruded-circle-solid.ifc with Revit 2020.1 and the current IFC export/import plugin. That seems to go very well. I imported the IFC models into an empty model (metric template). The only thing I had to do was changing the Phase created, from Phase 3 to Phase 1.

Regards, Dirk

[dvrvb]

for completeness, I also tested test-extruded-polygon-solid.ifc That one results in an empty family. But when I change the IFC, to make the 2nd statement active (yellow marked statement in screenshot), it is also opening well in Revit 2020.1

[jjkaelin]

Dirk, thank you very much for pointing out the Revit 2020 behavior with respect to model template and Phase. This solved my problem. This behavior is new for me and I did not run into this with Revit 2019.

To make it clear, I was using Open IFC into am empty (new) project, with the Default Template in IFC Options left empty (same as I did for Revit 2019). After importing one of the files attached in my first posting above using Open IFC, nothing is displayed in the view. The Phase shown in Properties for the Level 1 view (where I opened the IFC) is shown as Phase 1. If I change the Phase to Phase 3, the element is displayed and everything is fine. Phase Created in Properties is shown as Phase 3. This works for all three IFC files.

A better approach is, as you noted, to set a suitable template as the Default Template in IFC Options. Then no changes are needed in Phase and all three IFC files open correctly.

I do find the use of Phase shown under Properties confusing. I presumed that this field was a Revit property attached to the imported IFC. It seems however to act as a filter. And more confusing the default setting of Phase Filter to "Show All" does not show all phases. Maybe someone can explain this behavior?

For the file test-extruded-polygon-solid.ifc, this works fine if the ICTRIMMEDCURVE enumeration .UNSPECIFIED. is replaced with .CARTESIAN. as noted in my 2nd Update posting above.

Thanks again for your useful response.

[dvrvb]

Hi, Concerning the extruded-polygon: in my test it was also going well with the yellow marked statement (which is UNSPECIFIED).

I'm glad I could be of any help, but again, I'm sorry that I don't have no other useful experience with the import functionality. For me it was more the puzzle: it works in R2019, so it has to work in R2020, so the issue should be something else. Then the "what if" statement popped up with a notion "probably it is a visibility issue", so lets look to the phase. In some way I triggered you to use a template, but I did the job in a rude way, not even using or adjusting the IFC import options.

But now, you triggered me to do so, and indeed, if I use de Default Metric template, it works directly fine. The object is imported as "New construction" and is directly visible. Again, I did no other adjustment to the template or so: it was just a 'hit and run' action.

Concerning the functionality of Phase: if I read it correctly: to really show everything, you should use the option 'None': https://help.autodesk.com/view/RVT/2020/ENU/?guid=GUID-DB104358-4D5A-494E-ACAE-BB8B4E72E572 With the option "Show All" there could still be some overrides applicable.

Concerning the geometry of the extruded polygon: since there is an issue with the representation in BIM Vision, this is a nice example for sending to them. They are more than willing to get those things corrected. Regards, Dirk

[JOuellette-Autodesk]

@jjkaelin and @dvrvb Have you seen this behavior persist in 2022 or 2023?