[Solved] Unexpected results with IFC export of walls

[balrobs]

Hello to everyone,
when exporting walls to IFC I noticed a strange behaviour that I can't explain myself.
Wall_001 created by extruding a horizotal line along the z-axis and manipulated by a cut operation is OK but Wall_002 created by extruding a vertical wire along the x-axis seems to have problems (see below rapresentation in IFC++ and Blender). Is this a bug or is there a reason for it?

IFC_Walls.png (197 KiB) Viewed 2765 times

Code: Select all

OS: Windows 10 (10.0)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.22522 (Git)
Build type: Release
Branch: master
Hash: d8e476ef428017900dfe0f9359ba448503c216f9
Python version: 3.8.5
Qt version: 5.12.6
Coin version: 4.0.0
OCC version: 7.4.0
Locale: German/Germany (de_DE)

[bernd]

I can not confirm the problem ... I used the conda build

Code: Select all

OS: Windows 10 (10.0)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.22522 (Git)
Build type: Release
Branch: master
Hash: d8e476ef428017900dfe0f9359ba448503c216f9
Python version: 3.8.5
Qt version: 5.12.6
Coin version: 4.0.0
OCC version: 7.4.0
Locale: German/Switzerland (de_CH)

IFC_Walls_bernd.ifc

(5.02 KiB) Downloaded 87 times

screen.png (31.91 KiB) Viewed 2683 times

[balrobs]

I can not confirm the problem ... I used the conda build

Hi @Bernd,

Mmmh .. that's very strange. I used the conda build too. To be sure I downloaded and installed right now the latest conda build on my windows machine again and exported my above model one more time to a IFC-file ... same result
Can it depend on some wrong export parameter ???

IFC_Export_Parameter.png (53.24 KiB) Viewed 2669 times

Thank you for your time
balrobs

Code: Select all

OS: Windows 10 (10.0)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.22522 (Git)
Build type: Release
Branch: master
Hash: d8e476ef428017900dfe0f9359ba448503c216f9
Python version: 3.8.5
Qt version: 5.12.6
Coin version: 4.0.0
OCC version: 7.4.0
Locale: German/Germany (de_DE)

[bernd]

Damn the preferences. I should have know this is the problem ...

I ever time use "force export as Brep". All solids will be exported as a bound of faces instead as extrusions. This way the export is much much better. But one can not get back a wall or column object wich is based on a line or face.

If I deactivate it I can confirm the problem.

[balrobs]

Thanks @Bernd for your help and explanations.
Hopefully they can also be useful to other searchers in the forum here.
Cheers

[bernd]

We might change the standard pref to "force export as BREP" as it is much much more robust and does have much much less problems.

[Roy_043]

We might change the standard pref to "force export as BREP"

This is different from what you said a year ago:

If a solid is exported as brep it is just a bunch of faces. This is not smart because no one knows the thickness and the height of the wall later on. [...] We should not change the default export shape type to brep

[bernd]

We might change the standard pref to "force export as BREP"

This is different from what you said a year ago:

If a solid is exported as brep it is just a bunch of faces. This is not smart because no one knows the thickness and the height of the wall later on. [...] We should not change the default export shape type to brep

wow good find. Mhh at least I did say and still say it is not smart.

I would for sure prefere the extrusion export if it would work. Lately the users who work with FreeCAD and ifc export has extended and thus the people posting their findings on this forum. We had a few cases where the extusion export did not export the geometry correct last year. ATM there is noone who fixes all these bugs in the extrusion export a short period of time after the finding.

IMHO the most important is to export the correct geometry no matter if smart or not. Thus I changed my mind in this regard or at least I would start a disscussion about this.

cheers bernd