[ Solved ][ Ticket #4141: Multi-solid walls are not correctly exported to IFC ] Brep IFC export should be ON by default?

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Roy_043
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[ Solved ][ Ticket #4141: Multi-solid walls are not correctly exported to IFC ] Brep IFC export should be ON by default?

Postby Roy_043 » Wed Sep 18, 2019 8:31 am

I wonder if the 'Force export as Brep' option shouldn't be ON by default. If this option is OFF even simple models are not completely exported: in the example only one of the two walls that are based on the sketch is exported. I have imported the IFCs in FreeCAD to verify this.

Code: Select all

OS: Windows 8.1 (6.3)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.18234 (Git)
Build type: Release
Branch: master
Hash: 3af5d97e9b2a60823815f662aba25422c4bc45bb
Python version: 3.6.8
Qt version: 5.12.1
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: Dutch/Netherlands (nl_NL)
Attachments
BrepTest_Brep_ON.ifc
(4.07 KiB) Downloaded 36 times
BrepTest_Brep_OFF.ifc
(2.55 KiB) Downloaded 40 times
BrepTest.FCStd
(21.38 KiB) Downloaded 41 times
Last edited by Roy_043 on Mon Dec 09, 2019 10:09 am, edited 2 times in total.
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Roy_043
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Re: Brep IFC export should be ON by default?

Postby Roy_043 » Wed Sep 18, 2019 8:40 am

Just to be sure: Here are the other IFC import/export options. Everything still matches the default I believe.
Attachments
IFC_Options.png
IFC_Options.png (90.63 KiB) Viewed 1413 times
paullee
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Re: Brep IFC export should be ON by default?

Postby paullee » Wed Sep 18, 2019 12:20 pm

Roy_043 wrote: Wed Sep 18, 2019 8:31 am I wonder if the 'Force export as Brep' option shouldn't be ON by default. If this option is OFF even simple models are not completely exported: in the example only one of the two walls that are based on the sketch is exported. I have imported the IFCs in FreeCAD to verify this.
On mobile so can;t test the file -

Same problem ?

https://forum.freecadweb.org/viewtopi ... &t=31235
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Roy_043
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Re: Brep IFC export should be ON by default?

Postby Roy_043 » Wed Sep 18, 2019 1:19 pm

Yes exactly the same problem. Exporting with Brep 'ON' fixes your first example as well. Although the overlapping wall solids remain.
paullee
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Re: Brep IFC export should be ON by default?

Postby paullee » Wed Sep 18, 2019 4:52 pm

Yes, Export as Brep helps. Though I am not sure if it is better be described as kind of extrusion as originally in Wall itself in ifc for better compatibility?
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Roy_043
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Re: Brep IFC export should be ON by default?

Postby Roy_043 » Thu Sep 19, 2019 8:51 pm

@paullee: I am sorry, but I do not understand your last message.
paullee
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Re: Brep IFC export should be ON by default?

Postby paullee » Thu Sep 19, 2019 11:51 pm

I barely understand very very minimal things about ifc.

I remember it usually describe the base shape of an object, like a rectangle of a Wall. Then it describe the extrusion (something like extrusion height, direction etc.) of the Wall - very much like FC does ?

So with Brep export, whilst this would do much better for a complex shape that simple extrusion can't describe, I just wonder if there is any cons, like flexibility in / ease of further editing in ifc, compatibility with other soft.
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bernd
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Re: Brep IFC export should be ON by default?

Postby bernd » Fri Sep 20, 2019 7:06 am

if a solid is exported as brep it is just a bunch of faces. this is not smart because noone knows the thickness and the height of the wall later on. If it is exported as extrusion it is a line or polyline with a thickness and an extrusion length in z-direction.

If a wall is not exported as extrusion this is a bug somewhere and should be fixed. We should not change the default export shape type to brep IMHO.

bernd
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Roy_043
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Re: Brep IFC export should be ON by default?

Postby Roy_043 » Fri Sep 20, 2019 7:47 am

@bernd and @paullee:
Thank you both for clarifying.
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Roy_043
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Re: Brep IFC export should be ON by default?

Postby Roy_043 » Sat Sep 21, 2019 9:53 am

IMO it is wise to add this to the Bug Tracker. Which category should I use: Arch or File Formats?