Draft DXF: Difference between revisions

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<languages/>
{{GuiCommand|Name=Draft_DXF|Workbenches=[[Draft Module|Draft]]|MenuLocation=File -> Open/Import/Export}}
<translate>


<!--T:22-->
====Opening====
{{Docnav
|[[Draft_Preferences|Preferences]]
|[[Draft_SVG|Scalable Vector Graphics .SVG]]
|[[Draft_Module|Draft]]
|IconL=
|IconR=
|IconC=Workbench_Draft.svg
}}


</translate>
This function opens a DXF file (any version from 12 to 2007) in a new drawing.
{{TOCright}}
The following DXF object types are currently supported:
<translate>

==Description== <!--T:14-->

<!--T:15-->
Draft DXF is a software module used by the [[File:Std_Open.svg|24px]] [[Std_Open|Std Open]], [[File:Std_Import.svg|24px]] [[Std_Import|Std Import]] and [[File:Std_Export.svg|24px]] [[Std_Export|Std Export]] commands to handle the DXF file format.

</translate>
[[Image:Screenshot qcad.jpg]]
<translate>
<!--T:16-->
{{Caption|Qcad drawing exported to DXF, which is subsequently opened in FreeCAD}}

==Importing== <!--T:2-->

<!--T:27-->
Two importers are available, which one is used can be specified under {{MenuCommand|Edit → Preferences... → Import-Export → DXF}}. One is built-in, C++-based and fast, the other is legacy, coded in Python, slower, and requires the installation of an add-on, but can handle some entities better and can create more refined FreeCAD objects. Both support all DXF versions starting from R12.

<!--T:30-->
3D solids inside a DXF file are stored under a binary ACIS/SAT blob, which at the moment cannot be read by FreeCAD.

===C++ importer=== <!--T:31-->

<!--T:17-->
This importer can import the following DXF objects:
* lines
* lines
* polylines and lwpolylines
* polylines (and lwpolylines)
* arcs
* circles
* circles
* ellipses
* splines
* points
* texts and mtexts
* dimensions
* leaders
* blocks (only geometry, texts, dimensions and attributes inside blocks are skipped)
* layers
* paper space objects

===Legacy importer=== <!--T:32-->

<!--T:33-->
This importer can import the following DXF objects:
* lines
* polylines (and lwpolylines)
* arcs
* arcs
* circles
* layers (layers containing objects are conveted to FreeCAD Groups)
* ellipses
* splines
* 3D faces
* texts and mtexts
* texts and mtexts
* leaders
Other DXF entities, like blocks, etc... are currently not imported because there is no corresponding FreeCAD object. As new functionality gets implemented, it will be possible to import more entity types.
* layers

==Exporting== <!--T:4-->

<!--T:28-->
There are also two exporters. The legacy exporter exports to the R12 DXF format, the C++ exporter to the R14 DXF format. Both formats can be handled by many applications.

===C++ exporter=== <!--T:34-->

<!--T:35-->
Some of the features and limitations of this exporter are:
* All FreeCAD 2D geometry is exported, except [[Draft_CubicBezCurve|Draft CubicBezCurves]], [[Draft_BezCurve|Draft BezCurves]] and [[Draft_Point|Draft Points]].
* Straight edges from faces of 3D objects are exported, but curved edges only if they are on a plane parallel to the XY plane of the global coordinate system. Note that a DXF created from 3D objects will contain duplicate lines.
* Texts and dimensions are not exported.
* Colors are ignored.
* Layers are mapped from object names.

===Legacy exporter=== <!--T:36-->

<!--T:29-->
Some of the features and limitations of this exporter are:
* All FreeCAD 2D geometry is exported, except [[Draft_Point|Draft Points]]. But ellipses, B-splines and Bézier curves are not exported properly.
* 3D objects are exported as flattened 2D views.
* Compound objects are exported as blocks.
* Texts and dimensions are exported.
* The colors in the DXF are based on the line color of objects. Black is mapped to "ByBlock", other colors are mapped using AutoCAD Color Index (ACI) colors.
* Layers are mapped from layer and group names. When groups are nested, the deepest group gives the layer name.

==Installing== <!--T:8-->

<!--T:9-->
For licensing reasons, the required [[DXF|DXF]] import/export libraries needed by the legacy version of the importer are not part of the FreeCAD source code.
For more information see: [[FreeCAD_and_DXF_Import|FreeCAD and DXF Import]].

==Preferences== <!--T:26-->

<!--T:5-->
See [[Import_Export_Preferences|Import Export Preferences]].

== DWG == <!--T:39-->

<!--T:40-->
Because the DWG format is a proprietary, closed and undocumented format it is hard for open-source projects like FreeCAD to support it. That is why FreeCAD relies on external converters to read and write DWG files. To import a DWG file a converter is used to create a DXF first, which can then be processed by the FreeCAD DXF importer. When exporting to DWG the opposite conversion happens: the DXF created by the FreeCAD DXF exporter is turned into a DWG.

<!--T:41-->
Note that the DXF format allows a 1:1 conversion of the DWG format. All applications that can read and write DWG files can do the same with DXF files, with no data loss. So asking for DXF files instead of DWG files, and supplying DXF files in turn, should not cause any problems.

<!--T:42-->
There is built-in support for the following DWG converters:
* [https://www.gnu.org/software/libredwg LibreDWG] (open-source, lacks support for some DWG entities).
* [https://www.opendesign.com/guestfiles/oda_file_converter ODA File Converter] (free).
* [https://qcad.org/en/qcad-command-line-tools#dwg2dwg QCAD pro] (commercial). {{Version|0.20}}

<!--T:43-->
See [[Import_Export_Preferences#DWG|Import Export Preferences]] and [[FreeCAD_and_DWG_Import|FreeCAD and DWG Import]] for more information.

==Scripting== <!--T:37-->

<!--T:19-->
See also: [https://freecad.github.io/SourceDoc/ Autogenerated API documentation] and [[FreeCAD Scripting Basics|FreeCAD Scripting Basics]].

<!--T:20-->
To export objects to DXF use the {{incode|export}} method of the importDXF module.

</translate>
{{Code|code=
importDXF.export(objectslist, filename, nospline=False, lwPoly=False)
}}
<translate>

<!--T:38-->
* For the Windows OS: use a {{FileName|/}} (forward slash) as the path separator in {{Incode|filename}}.

<!--T:21-->
Example:

</translate>
{{Code|code=
import FreeCAD as App
import Draft
import importDXF

doc = App.newDocument()


polygon1 = Draft.make_polygon(3, radius=500)
====Importing====
polygon2 = Draft.make_polygon(5, radius=1500)


doc.recompute()
This works the same way as opening, but it will add the contents of the dxf file in the active documento instead of creating a new document.


objects = [polygon1, polygon2]
====Exporting====
importDXF.export(objects, "/home/user/Pictures/myfile.dxf")
}}
<translate>


The exported DXF is compatible with Autocad version 12 and up, so it should open in about any application that supports dxf format.
Currently the following FreeCAD objects get exported:
* lines, arcs and circles (single-edge Part shapes)
* polylines (Part wires)
* texts (Document annotations)
* colors are mapped from objects RGB colors to autocad color index (ACI). Black will always be "by layer"
* layers are mapped from group names. When groups are nested, the deepest group gives the layer name.


<!--T:6-->
====Preferences====
{{Docnav
|[[Draft_Preferences|Preferences]]
|[[Draft_SVG|Scalable Vector Graphics .SVG]]
|[[Draft_Module|Draft]]
|IconL=
|IconR=
|IconC=Workbench_Draft.svg
}}


</translate>
The following parameters can be specified in the Draft Preferences tab (menu Edit -> Preferences -> Draft):
{{Draft Tools navi{{#translation:}}}}
* Import style: This lets you choose the way objects from the dxf file will be drawn in FreeCAD. You can choose between:
{{Userdocnavi{{#translation:}}}}
** None: this is the faster way, there is no conversion, all objects will be black with 2px width (FreeCAD default)
[[Category:File Formats{{#translation:}}]]
** Use default color and linewidth: All imported dxf objects will take current linewidth/color from the draft command bar
** Original color and linewidth: Objects will keep the color and linewidth (if specified) they have in the dxf file
** Colors mapped to linewidth: If this option is selected, the mapping file option below is used.
* Color mapping file: This allows you to specify a mapping file to be used for translating dxf colors to color and linewidth, the same way as a plot style works in Autocad. The mapping file must be a tab-separated text file. There is a nice free utility called [http://www.noliturbare.com/TablePrintGUI.php Plot style viewer] that can convert Autocad CTB or STB (plot styles) files to tab-separated mapping files ready to use in FreeCAD. Alternatively, we have a couple of [[Draft_mapping_files|home-made mapping files]] availables here.
* Import texts: This allows you to specify if you want to import dxf texts or not. Many texts might make your work in FreeCAD very heavy, so you might want to use this option some time.
* Import layout objects: Turn this on if you want to import paper space object. They will be merged in the same document than model space objects.

Latest revision as of 15:48, 25 October 2021

Other languages:

Description

Draft DXF is a software module used by the Std Open, Std Import and Std Export commands to handle the DXF file format.

Qcad drawing exported to DXF, which is subsequently opened in FreeCAD

Importing

Two importers are available, which one is used can be specified under Edit → Preferences... → Import-Export → DXF. One is built-in, C++-based and fast, the other is legacy, coded in Python, slower, and requires the installation of an add-on, but can handle some entities better and can create more refined FreeCAD objects. Both support all DXF versions starting from R12.

3D solids inside a DXF file are stored under a binary ACIS/SAT blob, which at the moment cannot be read by FreeCAD.

C++ importer

This importer can import the following DXF objects:

  • lines
  • polylines (and lwpolylines)
  • arcs
  • circles
  • ellipses
  • splines
  • points
  • texts and mtexts
  • dimensions
  • leaders
  • blocks (only geometry, texts, dimensions and attributes inside blocks are skipped)
  • layers
  • paper space objects

Legacy importer

This importer can import the following DXF objects:

  • lines
  • polylines (and lwpolylines)
  • arcs
  • circles
  • ellipses
  • splines
  • 3D faces
  • texts and mtexts
  • leaders
  • layers

Exporting

There are also two exporters. The legacy exporter exports to the R12 DXF format, the C++ exporter to the R14 DXF format. Both formats can be handled by many applications.

C++ exporter

Some of the features and limitations of this exporter are:

  • All FreeCAD 2D geometry is exported, except Draft CubicBezCurves, Draft BezCurves and Draft Points.
  • Straight edges from faces of 3D objects are exported, but curved edges only if they are on a plane parallel to the XY plane of the global coordinate system. Note that a DXF created from 3D objects will contain duplicate lines.
  • Texts and dimensions are not exported.
  • Colors are ignored.
  • Layers are mapped from object names.

Legacy exporter

Some of the features and limitations of this exporter are:

  • All FreeCAD 2D geometry is exported, except Draft Points. But ellipses, B-splines and Bézier curves are not exported properly.
  • 3D objects are exported as flattened 2D views.
  • Compound objects are exported as blocks.
  • Texts and dimensions are exported.
  • The colors in the DXF are based on the line color of objects. Black is mapped to "ByBlock", other colors are mapped using AutoCAD Color Index (ACI) colors.
  • Layers are mapped from layer and group names. When groups are nested, the deepest group gives the layer name.

Installing

For licensing reasons, the required DXF import/export libraries needed by the legacy version of the importer are not part of the FreeCAD source code. For more information see: FreeCAD and DXF Import.

Preferences

See Import Export Preferences.

DWG

Because the DWG format is a proprietary, closed and undocumented format it is hard for open-source projects like FreeCAD to support it. That is why FreeCAD relies on external converters to read and write DWG files. To import a DWG file a converter is used to create a DXF first, which can then be processed by the FreeCAD DXF importer. When exporting to DWG the opposite conversion happens: the DXF created by the FreeCAD DXF exporter is turned into a DWG.

Note that the DXF format allows a 1:1 conversion of the DWG format. All applications that can read and write DWG files can do the same with DXF files, with no data loss. So asking for DXF files instead of DWG files, and supplying DXF files in turn, should not cause any problems.

There is built-in support for the following DWG converters:

See Import Export Preferences and FreeCAD and DWG Import for more information.

Scripting

See also: Autogenerated API documentation and FreeCAD Scripting Basics.

To export objects to DXF use the export method of the importDXF module. 

importDXF.export(objectslist, filename, nospline=False, lwPoly=False)
  • For the Windows OS: use a / (forward slash) as the path separator in filename.

Example: 

import FreeCAD as App
import Draft
import importDXF

doc = App.newDocument()

polygon1 = Draft.make_polygon(3, radius=500)
polygon2 = Draft.make_polygon(5, radius=1500)

doc.recompute()

objects = [polygon1, polygon2]
importDXF.export(objects, "/home/user/Pictures/myfile.dxf")


Draft
User documentation
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