[IFC EXPORT] Strange behavior on export

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walpa
Posts: 63
Joined: Wed Nov 09, 2016 5:22 pm
Location: Brazil

[IFC EXPORT] Strange behavior on export

Post by walpa »

Hi all,

Before exporting to IFC:
print_1.png
print_1.png (143.36 KiB) Viewed 1552 times
After export:
print_2.png
print_2.png (141.54 KiB) Viewed 1552 times

The element indicated in the figure changes position automatically and is exported in this new position (when imported into Blender, it is in the wrong place).

And the groups are being exported as IFCBUILDINGELEMENTPROXY and not IFCGROUP
print_3.png
print_3.png (93.38 KiB) Viewed 1552 times

Help, what am I doing wrong?

OS: Linux Mint 19.3 (X-Cinnamon/cinnamon)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.24291 (Git) AppImage
Build type: Release
Branch: (HEAD detached at 0.19.2)
Hash: 7b5e18a0759de778b74d3a5c17eba9cb815035ac
Python version: 3.8.8
Qt version: 5.12.9
Coin version: 4.0.0
OCC version: 7.4.0
Locale: Portuguese/Brazil (pt_BR)


Thanks
Attachments
Estrutural_to_export.FCStd.zip
(792.97 KiB) Downloaded 26 times
balrobs
Posts: 295
Joined: Fri Apr 24, 2020 8:58 pm

Re: [IFC EXPORT] Strange behavior on export

Post by balrobs »

I can confirm here.
Same when I open the exported IFC file in BIMcollab ZOOM.
Maybe a problem with the IFC exporter code?

Code: Select all

OS: Windows 10 Version 2009
Word size of FreeCAD: 64-bit
Version: 0.20.25452 (Git)
Build type: Release
Branch: master
Hash: b0b4b321cb7e90a15311c0a1deea35d618706733
Python version: 3.8.6+
Qt version: 5.15.2
Coin version: 4.0.1
OCC version: 7.5.0
Locale: German/Germany (de_DE)

Attachments
screebshot.JPG
screebshot.JPG (47.39 KiB) Viewed 1534 times
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Roy_043
Posts: 3741
Joined: Thu Dec 27, 2018 12:28 pm

Re: [IFC EXPORT] Strange behavior on export

Post by Roy_043 »

If I recompute the whole document the offending wall also changes position in FreeCAD.
balrobs
Posts: 295
Joined: Fri Apr 24, 2020 8:58 pm

Re: [IFC EXPORT] Strange behavior on export

Post by balrobs »

Roy_043 wrote: Wed Sep 01, 2021 5:32 pm If I recompute the whole document the offending wall also changes position in FreeCAD.
Yes! Even if I recompute only the offending wall its position changes. Obviously the culprit isn't the IFC exporter but some strangeness with the offending wall.
BTW moving the wall to its correct position solves the problem definitely.
Cheers!
walpa
Posts: 63
Joined: Wed Nov 09, 2016 5:22 pm
Location: Brazil

Re: [IFC EXPORT] Strange behavior on export

Post by walpa »

balrobs wrote: Thu Sep 02, 2021 7:46 am If I recompute the whole document the offending wall also changes position in FreeCAD.
Recompute hasn't changed anything here.
balrobs wrote: Thu Sep 02, 2021 7:46 am BTW moving the wall to its correct position solves the problem definitely.
Cheers!
Yes, I noticed that too.
In this (relatively small) project, this change is visible, but what if it was a big project and it happened without being identified? Reliability goes to space...
The procedure I used to draw this structural wall is the same as the others: create beam, select two points, then set parameters.
I did some testing and found that the order of selection of points in creating this wall/beam makes a difference. Left to right does not cause repositioning, right to left causes this behavior on export. I redid some beams changing the order of the points and the problem did not occur.
Strange... :)
Cheers too!
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bernd
Posts: 12392
Joined: Sun Sep 08, 2013 8:07 pm
Location: Zürich, Switzerland

Re: [IFC EXPORT] Strange behavior on export

Post by bernd »

have you tried to set "force brep" to true. This is not standard but higthly recomended to export robust models. With this setting to false there have seen various problems ....
balrobs
Posts: 295
Joined: Fri Apr 24, 2020 8:58 pm

Re: [IFC EXPORT] Strange behavior on export

Post by balrobs »

walpa wrote: Fri Sep 03, 2021 1:48 pm
balrobs wrote: Thu Sep 02, 2021 7:46 am If I recompute the whole document the offending wall also changes position in FreeCAD.
Recompute hasn't changed anything here.
In order to localize better the problem I took your file Estrutural_to_esport.FCStd, deleted everything except the object par-003 and saved it under Estrutural_to_export_01.FCStd.
Then I opened the new file, selected the object par-003 in the object-tree and with a right mouse click started the recompute-object command. The result was a flipping of the object. Notice that I only worked with FreeCAD files and objects and didn't use IFC at all. I also can't see any error messages!
BTW the interested object isn't a wall but a beam created with the BIM workbench, isn't it?
Maybe @Yorik can help us to understand what's going on here?
Cheers to all!

Here is my test file:
Estrutural_to_export_01.FCStd
(10.58 KiB) Downloaded 30 times
paullee
Posts: 3804
Joined: Wed May 04, 2016 3:58 pm

Re: [IFC EXPORT] Strange behavior on export

Post by paullee »

Suspected there is some hidden bug :-

Trying to play around what Arch Structure is capable and opened the OP's file.

Not only par-004 flip in direction, I had once revised the Height of par-004, and it also change direction ! But can't reproduce that.

Note both par-003 and par-004 have Axis-z = -1


Hope anyone has more idea :)

Screenshot from 2021-09-04 23-47-36.png
Screenshot from 2021-09-04 23-47-36.png (333.19 KiB) Viewed 1241 times
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thomas-neemann
Posts: 3823
Joined: Wed Jan 22, 2020 6:03 pm
Location: Osnabrück DE

Re: [IFC EXPORT] Strange behavior on export

Post by thomas-neemann »

walpa wrote: Wed Sep 01, 2021 3:07 pm
if you need a quick transitional solution, you could make a simple copy in part before the export and export it. it is enough to get the geometry.
falls ein video-link von mir schwarz und nicht anklickbar sein sollte, hier der kanal: https://www.youtube.com/channel/UCVcztV ... 03GgKekj_g
es ist auch möglich auf antworten zu klicken um den link zu sehen.
walpa
Posts: 63
Joined: Wed Nov 09, 2016 5:22 pm
Location: Brazil

Re: [IFC EXPORT] Strange behavior on export

Post by walpa »

bernd wrote: Sat Sep 04, 2021 11:13 am have you tried to set "force brep" to true. This is not standard but higthly recomended to export robust models. With this setting to false there have seen various problems ....
I tried but the behavior persisted.
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