Import Export Preference
The preferences for the importing and exporting tools are found in the Preferences Editor, in the menu Edit → Preferences → Import-Export.
The number of tabs varies depending on the file types available to perform conversion.
- Provided by the Arch Workbench: DAE, IFC
- Provided by the Draft Workbench: DWG, DXF, OCA, SVG
- Provided by the FEM Module: INP, VTK
- Provided by the Mesh Workbench: Mesh Formats
- Provided by the PartDesign Workbench: IGES, STEP
The Import-Export settings affect how files are imported and exported to and from FreeCAD. Note that the Import-Export preferences dialog offers file type settings for most workbenches but not every workbench is able to import/export all file types.
FreeCAD supports many file formats. For the following file formats it offers to apply special settings:
The Collada DAE (Digital Asset Exchange) format is a standard file format for exchange of Mesh data. The Arch workbench can import meshes from .dae files, and export Arch and other Shape-based objects to the .dae format. The Collada import functionality in the Arch module depends on pycollada. If it is not installed on your system, Collada import/export will be disabled.
For the DAE format you can specify the following:
|Scaling factor||All dimensions in the file will be scaled with the specified factor|
|Mesher||Sets the meshing program that should be used. If using Netgen, make sure that it is available. This can be checked by using the Mesh module and creating a mesh using Netgen. If it is not available another version of FreeCAD, compiled with Netgen, must be installed.|
|Tessellation||The tessellation value to use with the Builtin and the Mefisto meshing program.|
|Grading||The grading value to use for meshing using Netgen. This value describes how fast the mesh size decreases. The gradient of the local mesh size h(x) is bound by |Δh(x)| ≤ 1/value.|
|Segments per edge||The maximum number of segments per edge|
|Segments per radius||The number of segments per radius|
|Second order||Allow a second order mesh|
|Allow quads||Allow quadrilateral faces|
DWG (from drawing) is a proprietary binary file format used for storing two- and three- dimensional design data and metadata. Since it is a closed source file format it cannot be directly supported by FreeCAD. Therefore the external file converter ODA is required.
For the DWG format you can only specify the path to ODA. note: All settings for DXF file format also apply to DWG.
|Path to ODA (formerly Teigha) File Converter||Sets the path to the ODA file converter|
AutoCAD DXF (Drawing eXchange Format) is a proprietary format to exchange CAD data between AutoCAD and other programs.
For the DXF format you can specify the following:
|Show this dialog when importing and exporting||This preferences dialog will be shown when importing or exporting DXF files|
|Use legacy python importer||If checked, the Python importer is used, otherwise the newer C++ one. The C++ importer is faster, but has not as many features yet.|
|Use legacy python exporter||If checked, the Python exporter is used, otherwise the newer C++ one. The C++ exporter is faster, but has not as many features yet. introduced in version 0.19|
|Allow FreeCAD to automatically download and update the DXF libraries||By checking this, you will allow FreeCAD to download the Python converter for DXF import and export. This converter cannot be bundled with FreeCAD because it has a different software license.|
|Import|| Select what will be imported.|
If texts and dimensions is unchecked, texts and mtexts won't be imported.
If points is unchecked, points won't be imported.
If layouts is checked, paper space objects will be imported too.
Check *blocks if you want the non-named blocks (beginning with a *) to be imported too.
|Create|| Select what will be created.|
If simple Part shapes is selected, only standard Part objects will be created. This is the fastest.
If Draft objects is selected, parametric Draft objects will be created whenever possible.
If Sketches is selected, sketches will be created whenever possible.
|Scale factor to apply to imported files||Scale factor to apply to DXF files on import. The factor is the conversion between the unit of your DXF file and millimeters. Example: for files in millimeters: 1, in centimeters: 10, in meters: 1000, in inches: 25.4, in feet: 304.8|
|Get original colors from the DXF file||If checked, colors will be retrieved from the DXF objects whenever possible. Otherwise default colors will be applied.|
|Join geometry||If checked, FreeCAD will try to join coincident objects into wires. Note that this can take a while!|
|Group layers into blocks||If checked, objects from the same layers will be joined into Draft Blocks, turning the display faster, but making them less easily editable ??The Draft Wiki pages don't mention Draft blocks??|
|Use standard font size for texts||If checked, imported texts will get the standard Draft Text size, instead of the size they have in the DXF document|
|Use VisGroups||If checked, DXF layers will be imported as Draft VisGroups|
|Import hatch boundaries as wires||If checked, hatches will be converted into simple wires|
|Render polylines with width||If checked, if polylines have a width defined, they will be rendered as closed wires with the correct width|
|Treat ellipses and splines as polylines|| The export of ellipses and splines is poorly supported. Use this option to export them as polylines instead.|
The setting Max Spline Segment is then the maximum length of each of the polyline segments. If it is set to '0' the whole spline is treated as a straight segment.
|Export 3D objects as polyface meshes||If checked, all objects containing faces will be exported as 3D polyfaces|
|Export Drawing Views as blocks||If this is checked, Drawing Views will be exported as blocks. This might fail for post DXF R12 templates.|
|Project exported objects along current view direction||If checked, the exported objects will be projected to reflect the current view direction|
The Initial Graphics Exchange Specification (IGES) file format is a file format that allows the digital exchange of information among CAD systems. Since the specification for the STEP file format was published, the development of IGES was stopped in 1996. It is nevertheless still supported by many CAD programs.
|Units for export of IGES||Selection what unit will be used when exporting IGES files|
|Write solids and shells as|| Selection how solids and shells should be output.|
If Groups of Trimmed Surfaces (type 144) is selected, they will be exported as trimmed surface.
If Solids (type 186) and Shells (type 514) / B-REP mode is selected, solids will be exported as manifold solid B-Rep object, shells as shell.
|Skip blank entities||If checked, blank entities will not be imported|
|Company||If not empty, the entered text will be used in the IGES file header for the company|
|Author||If not empty, the entered text will be used in the IGES file header for the author|
|Product||If not empty, the entered text will be used in the IGES file header for the product|
For the IFC format you can specify the following:
|Show debug messages||Shows verbose debug messages during import and export of IFC files in the Report view panel|
|Create clones when objects have shared geometry||IFC objects can share a same geometry definition between several objects, only their placement is different. So when this option is enabled, clones are used to achieve the same result in FreeCAD. One object is the base object, the others are clones.|
|Import arch IFC objects as||What will be created in FreeCAD for arch IFC objects|
|Import struct IFC objects as||What will be created in FreeCAD for struct IFC objects|
|Root element||Only subtypes of the specified element will be imported. Keep the predefied element IfcProduct to import all building elements.|
|Separate openings||If checked, openings will be imported as subtractions, otherwise wall shapes will already have their openings subtracted.|
|Detect extrusions||If checked, the importer will try to detect extrusions. Note that this might slow things down.|
|Split multilayer walls||Split walls made of multiple layers|
|Prefix names with ID number||If checked, object names will be prefixed with the IFC ID number.|
|Merge materials with same name||If several materials with the same name are found in the IFC file, they will be treated as one.|
|Import Ifc Properties in spreadsheet||If checked, each object will have their IFC properties stored in a spreadsheet object.|
|Exclude list||A comma-separated list of IFC entities to be excluded from imports|
|Fit view while importing||Fit view during import on the imported objects. This will slow down the import, but one can watch the import.|
|Import full FreeCAD parametric definitions if available|| Creates a full parametric model on import using stored FreeCAD object properties.|
To get the FreeCAD properties, the model must have been exported using the option Export full FreeCAD parametric model. introduced in version 0.19
|Force export as Brep||Some IFC viewers don't like objects exported as extrusions. Use this to force all objects to be exported as BREP geometry.|
|Use DAE triangulation options||Use triangulation options set in the DAE options page|
|Join coplanar facets when triangulating||Curved shapes that cannot be represented as curves in IFC are decomposed into flat facets. If this is checked, some additional calculation is done to join coplanar facets.|
|Store IFC universal ID in FreeCAD objects||When exporting objects without unique ID (UID), the generated UID will be stored inside the FreeCAD object for reuse next time that object is exported. This leads to smaller differences between file versions.|
|Use IfcOpenShell serializer if available|| IFCOpenShell is a library that allows to import IFC files. Its serializer functionality allows to give it an OCC shape and it will produce an adequate IFC geometry: NURBS, faceted, or anything else.|
Note that the serializer this is still an experimental feature.
|Export 2D objects as IfcAnnotations||If checked, 2D objects will be exported as IfcAnnotation|
|Export full FreeCAD parametric model||If checked, all FreeCAD object properties will be stored inside the exported objects, allowing to recreate a full parametric model on reimport using the option Import full FreeCAD parametric definitions if available.|
|Reuse similar entities||If checked, similar entities will be used only once in the file if possible. This can reduce the file size a lot, but will make it less easily readable.|
|Disable IfcRectangleProfileDef||When possible, IFC objects that are extruded rectangles will be exported as IfcRectangleProfileDef. However, some other applications might have problems importing that entity. If this is your case, you can disable this and then all profiles will be exported as IfcArbitraryClosedProfileDef.|
|Auto-detect and export as standard cases when applicable||Some IFC types such as IfcWall or IfcBeam have special standard versions like IfcWallStandardCase or IfcBeamStandardCase. If this option is turned on, FreeCAD will automatically export such objects as standard cases when the necessary conditions are met. introduced in version 0.19|
|Add default site if one is not found in the document||When exporting an IFC file, if no site is found in the FreeCAD document, a default one will be added. A site is not mandatory by the IFC standard, but a common practice to have at least one in the file. introduced in version 0.19|
|Add default building if one is not found in the document (no standard)|| When exporting an IFC file, if no building is found in the FreeCAD document, a default one will be added.|
Warning: The IFC standard asks for at least one building in each file. By turning this option off, you will produce a non-standard IFC file.
However, at FreeCAD, we believe having a building should not be mandatory, and this option is there to have a chance to demonstrate our point of view. introduced in version 0.19
|Add default building storey if one is not found in the document||When exporting an IFC file, if no building storey is found in the FreeCAD document, a default one will be added. A building storey is not mandatory by the IFC standard, but a common practice to have at least one in the file. introduced in version 0.19|
The tab Abaqus INP is only shown in the preferences if you are or if you have been in the FEM workbench before.
For the INP format you can specify the following:
|Which mesh elements to export|| Selection what mesh element parameters should be exported.|
If All is selected, all elements will be exported.
If Highest is selected, only the highest elements will be exported. This means for means volumes for a volume mesh and faces for a shell mesh.
If FEM is selected, only FEM elements will be exported. This means only edges not belonging to faces and faces not belonging to volumes.
|Export group data||If checked, mesh groups are exported too. Every constraint and, if there are different materials, material consists of two mesh groups, faces and nodes where the constraint or material is applied.|
Meshes are a special type of 3D object, composed of triangular faces connected by their vertices and edges. They are widely used for additive manufacturing. The FreeCAD provides the Mesh workbench to create and handle meshes. FreeCAD supports the file formats AMF and its predecessor STL, OBJ, OFF, PLY and SMF.
The tab Mesh Formats is only shown in the preferences if you are in the Mesh workbench or if you have been in this workbench before.
For the Mesh formats you can specify the following:
|Maximum mesh deviation||Specification of the maximal deviation between the mesh and the object|
|Export AMF files using compression||If checked, ZIP compression is used when writing a mesh file in AMF format|
The OCA file format is a community project to create a free, simple and open CAD file format. OCA is largely based on the GCAD file format generated by gCAD3D. Both formats can be imported in FreeCAD and the OCA files exported by FreeCAD can be opened in gCAD3D.
For the OCA format you can specify the following:
|Import OCA areas||If checked, the areas (3D faces) will be imported too|
The standard for the exchange of product model data (STEP) file format is an ISO standard for the computer-interpretable representation and exchange of product manufacturing information. STEP is therefore commonly used to exchange 3D data between CAD software. STEP files have the suffix .step or sometimes .stp.
|Units for export of STEP||Selection what unit will be used when exporting STEP files|
|Write out curves in parametric space of surface||If checked, parametric curves (curves in parametric space of surface) will be written into the STEP file. Unchecking the option can be helpful to minimize the size of the resulting STEP file.|
|Scheme|| Selection what STEP application protocol (AP) will be used for the export.|
AP 203 is the protocol for configuration controlled 3D designs of mechanical parts and assemblies.
AP 204 is the protocol for core data for automotive mechanical design processes.
|Enable STEP Compound merge||If checked, a compound merge will be done during file reading. This is slower but results in higher details.|
|Company||If not empty, the entered text will be used in the STEP file header for the company|
|Author||If not empty, the entered text will be used in the STEP file header for the author|
|Product||If not empty, the entered text will be used in the STEP file header for the product|
Scalable Vector Graphics (SVG) is a vector image format for two-dimensional graphics. The vectors make SVG are very useful for technical drawing programs like FreeCAD's TechDraw because a vector image can be scaled to any size without losing its shape or amount of details. SVG can be scaled to any required resolution and converted to bitmap formats like PNG or JPEG for printing.
For the SVG format you can specify the following:
|Import style|| Selection how SVG object colors and line widths will be imported.|
If None (fastest) is selected no color and line width settings will be imported.
If Use default color and linewidth is selected FreeCAD will use its default color and line width.
If Original color and linewidth is selected FreeCAD will use the color and linewidth from the SVG objects.
|Disable units scaling||If checked, no units conversion will occur. One unit in the SVG file will translate as one millimeter.|
|Export style|| Selection how Sketches are exported to SVG.|
If Translated (for print & display) is selected, SVG objects are encapsulated in a group that is scaled and moved to the correct place in the SVG document to fit into a printable area.
If Raw (for CAM) is selected, SVG objects are placed as they are - at the same coordinates as in the FreeCAD model (1:1 export).
|Translate white line color to black||If checked, all white lines will appear in black in the SVG for better readability against white backgrounds|
|Max segment length for discretized arcs||Versions of Open CASCADE older than version 6.8 don't support arc projection. In this case arcs will be discretized into small line segments. This value is the maximum segment length.|
The Visualization Toolkit (VTK) is an open-source, freely available software system for 3D computer graphics, image processing and visualization. VTK files are used by the FEM workbench for the post processing of simulation results.
The tab VTK is only shown in the preferences if you are or if you have been in the FEM workbench before.
For the VTK format you can specify the following:
|Which object to import into|| Selection what objects should be imported.|
If VTK result object is selected, a FreeCAD FEM VTK result object will be imported (equals to the object which was exported).
If FEM mesh object is selected, the results in the VTK file will be omitted, only the mesh data will be imported and a FreeCAD FEM mesh object will be created.
If FreeCAD result object is selected, the imported data will be converted into a FreeCAD FEM Result object. Note: this setting needs the exact result component names and thus it only works properly with VTK files exported from FreeCAD.