[FIXED] DWG/DXF export fails with "AcDbDictionary" error

[aapo]

Hi!

It seems that the DWG/DXF export of a part fails with "AcDbDictionary" error when the part gets more complicated, and apparently the dictionary somehow gets overflown. The ODA File Converter fails with the following error:

Code: Select all

OdError thrown during readFile of drawing "20191016-DWG-export-bug.dxf" :
  Object of class AcDbLine can't be cast to AcDbDictionary.

However, I think the problem lies with the DXF export, as some other CAD programs seem to have problems with the DXF files that FreeCAD produces, if the files are "too" complicated. I have attached a file, which has a simple circular plate with some hole sectors made with the polar pattern tool. If I make 10 or less holes, the DWG export works; but 11 or more holes I get an error. It is fairly repeatable by just changing the number of holes in the polar pattern object, and trying to export. The FCStd file showing the problem is attached.

Please note that the FreeCAD DXF export itself does not fail, even with 12 holes. Also, FreeCAD (and, e.g., IrfanView) can open the resulting DXF files fine; but some other programs like ODA File Converter have problems.

20191016-DWG-export-bug-pic1.png (41.71 KiB) Viewed 1642 times

20191016-DWG-export-bug-pic2.png (36.18 KiB) Viewed 1642 times

OS: Windows 10 (10.0)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.18504 (Git)
Build type: Release
Branch: master
Hash: f66023a646db4b2502bb3637897443b3525ca3c7
Python version: 3.6.8
Qt version: 5.12.1
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: English/United Kingdom (en_GB)

[wandererfan]

It seems that the DWG/DXF export of a part fails with "AcDbDictionary" error when the part gets more complicated, and apparently the dictionary somehow gets overflown. The ODA File Converter fails with the following error:

Are you using the Draft module ("legacy") exporter or the Import module ("c++" or "new") exporter?

ODA didn't complain about these conversions, but I don't have anything else that reads DWG files. How do they look for you?

[UR_]

Autodesk TrueView

12 holes - error (recover needed)

Screenshot 002.png (14.28 KiB) Viewed 1602 times

Screenshot 003.png (10.26 KiB) Viewed 1602 times

9 holes - no errors

Screenshot 004.png (47.51 KiB) Viewed 1602 times

[wandererfan]

Autodesk TrueView

Thanks! Try another one?

ADViewer_F00.png (58.71 KiB) Viewed 1574 times

[aapo]

Are you using the Draft module ("legacy") exporter or the Import module ("c++" or "new") exporter?

Not 100 % sure, but I think I'm using the Import module ("c++" or "new") exporter. I used PartDesign workbench, selected the part, and chose File->Export. I don't think I have the "legacy" dxf exporter installed at all, as I generally don't use the Draft module in my work flow, and as such I haven't installed any draft-related extras.

OS: Windows 10 (10.0)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.18504 (Git)
Build type: Release
Branch: master
Hash: f66023a646db4b2502bb3637897443b3525ca3c7
Python version: 3.6.8
Qt version: 5.12.1
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: English/United Kingdom (en_GB)

[wandererfan]

Should be fixed by git commit 5512d5490c.

[aapo]

Should be fixed by git commit 5512d5490c.

At long last, today, the Windows Travis builds of v0.19 in Github reached a version 18615, which contains your commit, and I was able to test the bug fix (my Linux build system doesn't have any DWG capability, and on Windows I don't have a build system). Anyway, I can confirm this fixed both the DXF and DWG issues with parts containing multiple holes. Thanks a thousand for the fix, this really helped me to deliver some drawings for steel laser cutting, and hopefully any new users won't need to stumble upon this problem, as the fix is now in the master.


OS: Windows 10 (10.0)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.18615 (Git)
Build type: Release
Branch: master
Hash: a801ff5a236d9275c2dc184db5a457589b3eabc4
Python version: 3.6.7
Qt version: 5.12.1
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: English/United Kingdom (en_GB)