Editing Drawing (DWG)

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The Drawing (DWG) file format developed by [https://en.wikipedia.org/wiki/Autodesk Autodesk] is a proprietary file format and the native file format for a number of proprietary CAD systems. The [[Drawing Exchange Format (DXF)]] is usually a better alternative for free software as it has better support for virtually the same content.

Wikipedia has a good article about [https://en.wikipedia.org/wiki/.dwg the DWG format and it's history].

=DWG in FOSS Software=

There have been two efforts at making a free software library for reading/writing DWG. 
* [[libdxfrw]] which is the default DXF/DWG library for [[LibreCAD]] (versions 2 & 3)
* [[LibreDWG]] which is more advanced but in beta state

You can read about the struggles of supporting DWG in free software in the [http://libregraphicsworld.org libregraphicsworld] article [http://libregraphicsworld.org/blog/entry/libredwg-revived-starts-getting-regular-releases LibreDWG revived, starts getting regular releases]

==Free software known to have some support for DWG==
* [[FreeCAD]] uses [[LibreDWG]] from version 0.19 for Linux builds and Conda Windows builds. Otherwise check the [https://wiki.freecadweb.org/FreeCAD_and_DWG_Import FreeCAD documentation] or ask in our forum.
* [https://github.com/tercoide/GauchoCAD GauchoCAD] uses [[LibreDWG]] but is currently alpha software with no released packages
* [[LibreCAD]] has basic DWG support using the [[libdxfrw]] library
* [[SolveSpace]] can import DXF and DWG and export 2D sketches and 3D wireframes as DXF using the [[libdxfrw]] library. Moving to [[LibreDWG]] is under discussion.
* [[QCAD]] has a commercial version which adds DWG support using the non-free ODA Teigha Library.
* [[ZCAD]] is a simple CAD program, written in Lazarus / FPC. It can open and save DXF2000 files. They are actively working on DWG support with the [[LibreDWG]] library.

==Current status of LibreDWG==

Generally LibreDWG is stable for the most common entities and objects for DWG and DXF, plus hundreds more. It can write DWG r2000 already, plus all DXF versions. DWG write support for 2004-2018 is about 80% done. See also [https://lists.gnu.org/archive/html/libredwg/2020-12/threads.html LibreDWG discussion list] and [https://savannah.gnu.org/news/?group=libredwg LibreDWG news]

Please test and [https://github.com/LibreDWG/libredwg/issues report bugs].

There is currently focus on gambas bindings (that's the free GNU VBA variant) for GauchoCAD and C++ bindings for SolveSpace. Perl and python bindings are ready but unused.

'''Current limitations:'''
* Not feature parity with [[Open_Design_Alliance_(ODA)]]
* Many basic dynamic blocks and parametrics are done but it's still a work in progress.
* DWG write support for 2004-2018 is about 80% done, still some bugs.
* Creating 3dsolids from scratch, writing acis data is also not yet good enough.
* The objects and fields are all done, but it's undocumented and unstable.
* lisp bindings, like for guile would be nice, but low priority (no one has asked for it)

=See also=
* [[Libdxfrw]] is the DXF / DWG library used by [[LibreCAD]]
* [[Drawing Exchange Format (DXF)]]
* [[Open_Design_Alliance_(ODA)]]
* [[FreeCAD]]
* [[GambasCAD]]
* [[Getting started with 2D CAD drafting]]

=External Resources=
* The [https://www.opendesign.com Open Design Alliance] has a freely available proprietary [https://www.opendesign.com/guestfiles/oda_file_converter ODA File Converter] for converting between different versions of .dwg and .dxf
* The ODA has [https://www.opendesign.com/files/guestdownloads/OpenDesign_Specification_for_.dwg_files.pdf published a DWG specification]
* [https://en.wikipedia.org/wiki/.dwg DWG at Wikipedia] gives background on the way Autodesk has pursued anyone trying to achieve compatability.

[[Category:Drawing (DWG)]]
[[Category:Drawing_Exchange_Format_(DXF)]]
[[Category:File formats]]