Description
Draft DXF is a software module used by the 
Std Open, 
Std Import and 
Std Export commands to handle the DXF file format.
From the user's point of view, the DXF import/export module will be loaded automatically when any of those commands are invoked and the file to open, import or export is a DXF file. The main difference between Std Open and the import command is that the former will create a new FreeCAD document and then do the import, whereas the later will import the DXF file and insert the result in the currently active document.
QCAD drawing exported to DXF, which is subsequently opened in FreeCAD
Otevírání
Tato funkce otevírá soubory DXF (jakoukoliv verzi od 12 do 2007) v novém výkresu. V současné době jsou podporovány následující objekty DXF:
- přímky
- lomené čáry a lwpolylines
- kružnice
- oblouky
- vrstvy (vrstvy obsahující objekty jsou konvertovány do skupin FreeCADu)
- texty a mtexty
- kótování
- bloky (pouze konstrukce; texty, kóty a atributy uvnitř bloků jsou přeskočeny)
- body introduced in 0.13
- vynášecí čáry introduced in 0.13
Ostatní DXF entity nejsou v současné době importovány, protože zatím nejsou ve FreeCADU implementovány korespondující objekty. Jakmile budou implementovány nové funkcionality, bude pravděpodobně možné importovat více typů entit.
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.
| Entity | C++ importer | Legacy importer |
|---|---|---|
| Lines | ✓ | ✓ |
| Polylines (and LWPOLYLINES) | ✓ | ✓ |
| Arcs | ✓ | ✓ |
| Circles | ✓ | ✓ |
| Ellipses | ✓ | ✓ |
| Splines | ✓ | ✓ |
| Texts & MTexts | ✓ | ✓ |
| Leaders | ✗ | ✓ |
| Layers | ✓ | ✓ |
| Points | ✓ | ✓ |
| Dimensions | ✓ | ✓ |
| Blocks | ✓ (Geometry only; texts, dimensions, and attributes inside blocks are skipped) |
✓ |
| Paper space objects | ✓ | ✓ |
| 3D Faces | ✗ | ✓ |
Exportování
Exportovaný DXF je kompatibilní s Autocadem verze 12 a vyšší, takže by mělo být možné jej otevřít v jakékoliv aplikaci, která podporuje DXF formát. V současnosti jsou exportovány následující objekty FreeCADu:
- přímky a dráty (lomené čáry)
- oblouky a kružnice
- texty
- barvy jsou mapovány z RGB barev objektů na indexy barev Autocadu (ACI). Černá bude vždy "podle vrstvy"
- vrstvy jsou mapovány z názvů skupin. Jsou-li skupiny "zahnízděny" (skupina ve skupině), pak je jméno vrstvy podle nejhlubší skupiny.
- kóty, které jsou exportovány ve "Standardním" stylu kót
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.
| Feature | C++ exporter (R14) | Legacy exporter (R12) |
|---|---|---|
| Supported 2D Geometry | All except Bezier curves. Ellipses and Splines are exported natively. | All except Points. Ellipses and B-splines may be inaccurate or exported as polylines. |
| Points | ✓ (If the "Export points" preference is enabled) |
✗ |
| 3D Objects | Edges from faces are exported. Curved edges only if on XY plane. May create duplicate lines. | Exported as flattened 2D views. |
| Texts and Dimensions | ✗ | ✓ |
| Colors | ✗ | ✓ (Based on object line color) |
| Layers | ✓ (Mapped from object names) |
✓ (Mapped from layers and nested groups) |
| Compounds | ✗ | ✓ (Exported as blocks) |
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:
- LibreDWG (open-source, lacks support for some DWG entities).
- ODA File Converter (free).
- QCAD pro (commercial).
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")
Tato stránka je načtena z https://wiki.freecad.org/Draft_DXF