import export CAD file format

http://www.okino.com/conv/filefrmt_cad.htm

The following table lists the suggested or preferred 3D file formats and methods to be used when importing from a known 3D CAD program. The numbers beside each checkmark specify the order of preference amongst the various file formats which can be exported from each CAD program.Click on the red "Notes" link to read other suggestions. Click on the file format names at the top of the table to view the online Okino importer documentation.

The preferences and suggestions listed below are culled from a decade or more of experience from Okino developers and from daily two-way feedback with our customers. We hope that some of our comments provided in the "Notes" sections will help educate our customers to the preferred methods to export data from a specific CAD-based package, and to dispel common misconceptions about specific file formats and data conversion processes that exist in the 3D industry (for example, see the notes for Microstation and Pro/E).

CAD Program	Native	DWG DXF	IGES	Para- solids	SAT	STL SLP	VDA	VRML 1 or 2	XGL ZGL	Other
Autodesk AutoCAD										.3ds
+ Notes: The two best formats to export data from AutoCAD into Okino products are DWG (the native binary file format of AutoCAD) or DXF (the native ASCII file format of AutoCAD) and the ACIS SAT file format. The core of AutoCAD is based on the ACIS solids modeling kernel, so the ACIS .sat file format is a natural choice for exporting solids-based data with no loss in quality. The .3ds file format is another mesh-based export method. The least recommended file format is .stl since it only outputs raw mesh data and nothing else. Importing into AutoCAD is strictly by DXF and DWG file formats.
Autodesk Inventor										STEP
+ Notes: The best method to export data from Autodesk Inventor into Okino products is via the native Autodesk Inventor importer written by Okino. This will import assembly and part data from a live running copy of Inventor or from disk-based Inventor files; no resident copy of Inventor is needed to read from the disk-based files.Other methods to export from Inventor are: ACIS SAT, IGES, STEP, STL and XGL/ZGL. Importing into Inventor can be done via DXF/DWG files, IGES, native ProE .asm/.prt, ACIS .sat or STEP. In these cases the files must contain 'solids' based data and not mesh polygon data. Exporting solids-based files is not done by Okino products, except if you can import NURBS surfaces and export to IGES in which case Inventor will try to stitch the NURBS back into solids.
ArchiCAD										.3ds
+ Notes: ArchiCAD is a popular architectural package developed by Graphisoft Corp.Exportable file formats from ArchiCAD are DXF/DWG, .3ds and DGN.
Autodesk ADT
+ Notes: Autodesk Architectural Desktop is built on top of AutoCAD. As such, importing from Autodesk Architectural Desktop into Okino products is similar to that of AutoCAD. DWG/DXF and ACIS SAT are the natural file formats. STL is the least desired method.
Autodesk MDT
+ Notes: Importing from Autodesk Mechanical Desktop into Okino products is similar to that of AutoCAD. DWG/DXF and ACIS SAT are the natural file formats. STL is the least desired method.
CADKEY										STEP
+ Notes: CADKEY has good support for exporting to all of the major 3D file formats, including ACIS SAT, IGES, Parasolids, STEP and STL. STL is the least desireable format to use. Recommended formats for importing CADKEY data into Okino software is ACIS SAT, IGES and then Parasolids.
CATIA v4
+ Notes: Import of CATIA v4 .model, .exp, .dlv and .session files is best done with the Okino native CATIA v4 importer. This geometry import converter imports and processes BREP solids-based CAD geometry files stored in the CATIA v4 native file formats. Okino has been a trained Spatial Corp. developer since 1997, resulting in a top notch, refined and professional implementation of the Okino-CATIA importer. The CATIA stand-alone program (made by Dassault Systèmes and distributed by IBM) is an integrated suite of Computer Aided Design (CAD), Computer Aided Engineering (CAE), and Computer Aided Manufacturing (CAM) applications for digital product definition and simulation. It allows manufacturers to simulate all the industrial design processes, from the pre-project phase, through detailed design, analysis, simulation, assembly and maintenance. CATIA is primarily used by the automotive and aerospace industries for automobile and aircraft product and tooling design (it is well known for being used by Boeing to design their massive airplanes, or NASA to help design the Space Shuttle). There are roughly 20,000 companies worldwide using CATIA with roughly 30,000 seats sold per year.
CATIA v5
+ Notes: Import of CATIA v5 .CATPart and .CATProduct files is best done with the Okino native CATIA v5 importer. This geometry import converter imports and processes BREP solids-based CAD geometry files stored in the CATIA v5 native part and assembly file formats. The importer is based on the actual CATIA v5 runtime DLLs and components from Dassault Système (the developers and owners of the CATIA v5 modeling software) and hence provides the absolute best conversion of native CATIA v5 part and assembly files - no reverse engineered libraries are used, as is often the case with other CATIA v5 importers. The CATIA stand-alone program (made by Dassault Systèmes and distributed by IBM) is an integrated suite of Computer Aided Design (CAD), Computer Aided Engineering (CAE), and Computer Aided Manufacturing (CAM) applications for digital product definition and simulation. It allows manufacturers to simulate all the industrial design processes, from the pre-project phase, through detailed design, analysis, simulation, assembly and maintenance. CATIA is primarily used by the automotive and aerospace industries for automobile and aircraft product and tooling design (it is well known for being used by Boeing to design their massive airplanes, or NASA to help design the Space Shuttle). There are roughly 20,000 companies worldwide using CATIA with roughly 30,000 seats sold per year.
CoCreate Designer										STEP
+ Notes: "OneSpace Designer" is a product of CoCreate Corp. Native file formats are ACIS SAT, IGES and STEP.
Cosmos										STEP
+ Notes: Structural Research & Analysis Corporation (SRAC) develops and markets design analysis software products for the mechanical computer-aided engineering market. It includes CAD file format compatibility via IGES, ACIS, Parasolids and STEP. RealityWave Corp. mentions that an XGL/XGL exporter is available for Cosmos products.
Form/Z										See Notes
+ Notes: Form/Z is one of those power house 3D modelers. Being a top notch modeler it has many methods to export 3D geometry data to other 3D programs. Of note are: 3ds, ACIS SAT, DXF/DWG, IGES, STL, VRML and Wavefront OBJ.
I-DEAS
+ Notes: Okino's VRML importers were tweaked in their early days to specifically import VRML files from EDS's I-DEAS; this is the preferred method of data translation. Other supported formats are IGES, STL and VDA-FS.
Microstation										** STEP
+ Notes: If we had to put one program and one file format into a category and class of its own, it would be Microstation. Okino has a very long history of wishing to get a clean data conversion pipeline out of Microstation. In the mid-90's the export file formats were quite limited (DGN, IGES, RIB) and our direct programmer-level experience showed that the exported IGES files were not compatible with the IGES file format rules (in particular, customer IGES files had self-intersecting trimming curves, overlapping trim loops, trim loops which crosssed the outer patch boundaries, etc).Fortunately the robustness and number of the 3D geometry exporters in Microstation has matured greatly over a period of 9 years. There are now multiple 3D file formats which can be used to convert Microstation data to other file formats (sorted by our current personal preference of best formats to use with Microstation data exports): STEP AP203 & AP214 ACIS SAT Parasolids v13 and newer VRML 2.0 (including animation support) AutoCAD DWG and DXF IGES, "Export Surface Only" VRML 1.0 For as much as the DGN is the native external file format of Microstation, the best file formats to export data from Microstation in the past, in our long experience, were definitely ACIS SAT and VRML. Even so, all of the file formats in the list above are supported by the Okino importers. Microstation is built upon the 'Parasolids' solids modeling toolkit; as such, it is always better to export in a "solids based" file format (such as Parasolids .x_t, ACIS .sat or STEP) than the DGN format. Our latest experience with testing all the various formats listed above with customer data has shown that STEP, then ACIS SAT, then Parasolids files exported from Microstation and imported into Okino software via the corresponding Granite/Pack importers work best. The bottleneck in the conversion pipeline, as has been the case for many years, is the Microstation exporters, and the manner in which they partially or fully export their 3D scene data. XGL and ZGL files can also be used if they are first created in JSpace MicroStation CAD Connection in MicroStation TriForma v8 or newer.
PTC Pro/DESKTOP
+ Notes: Pro/DESKTOP is a solids modeler from PTC Corp. A free version, Pro/DESKTOP Express, is also available for download from their WEB site.Native Pro/DESKTOP files can be imported into Okino software via the Pro/DESKTOP importer provided in the Okino CAD/Pack add-on license.
PTC Pro/Engineer										OBJ, JT
+ Notes: Okino has a long history of supporting and selling to Pro/Engineer users, and for moving Pro/Engineer data files into all major 3D file formats and animation packages.Suggestion: If your ProE assemblies are massive, then we recommend that you first "Shrink Wrap" them first inside ProE prior to export. In many cases this will significantly reduce the size and complexity of the exported model. An Okino customer has several excellent methods to get Pro/E data into Okino software: Since 1996 the standard method has been the Okino IGES importer, of which it itself has been in development since 1988. The Okino IGES importer has been written in particular to support ProE IGES files, and works perfectly with them. In all our experience, ProE outputs the cleanest and best surface-based IGES files of any CAD package we have dealt with. Another obvious choice is the native ProE importer that Okino has licensed directly from PTC and is provided in the "Granite/Pack". This will import the solids-based ProE parts and convert them to mesh models before placing them in an assembly hierarchy. A simple, yet effective method, is to export data in the "ProE Render File" format. This exports the entire assembly as one huge clump of polygons, with no hierarchy, part naming or other attribute information. You will have to first tag each part in your assembly with a different and unique color. Once the SLP file has been imported into Okino software it will be re-exploded back into unique parts based on the assigned colors. If your ProE assembly is not too large, then this is an acceptable import method. Wavefront OBJ is another possible method to export data from ProE, but Okino has simply never recommended it because the IGES and SLP file formats work so well. The benefit of the Okino IGES import route is that the data remains as trimmed NURBS in the internal Okino scene graph, and thus can be re-exported as trimmed NURBS to programs and file formats such as Softimage-3D, Renderman, OpenNURBS, etc. The benefit of the native PTC ProE importer is that the BREP stitching data within the files will be used to create ideal crack-free tessellated mesh models.
Solid Edge										STEP
+ Notes: The defacto best way to transfer data from Solid Edge into Okino software is via the native Solid Edge importer written by Okino. This will import a mesh representation of a Solid Edge assembly (with hierarchy and material information) from either disk-based files, or from a live running copy of Solid Edge. In the former case, no local copy of Solid Edge will be required.The second most recommended file format would be XGL. Other formats exported from Solid Edge are ACIS SAT, IGES, Parasolids and STEP. Individual parts can also be exported as STL.
SolidWorks										See Notes
+ Notes: Regardless of whether you own a copy of the SolidWorks application, the recommended method to import CAD data from SolidWorks .sldasm and .sldprt files is via the Okino native SolidWorks importer, available and supported since 1998. It is one of our top 3 requested CAD importers and will import from a live running copy of SolidWorks or from disk-based files when no local copy of SolidWorks is available.ZGL file format is another excellent, non-native method, to import data from SolidWorks. We would also normally recommend IGES as an ideal route to import from any CAD package, but in the case of SolidWorks the native .sldasm and .sldprt file importer and ZGL are more straightforward conversion paths. Other formats exported from SolidWorks are ACIS SAT, IGES, Parasolids, STL, STEP, VDA-FS, VRML-1 and VRML-2.
Think3										STEP
+ Notes: Supported file formats from the Think3 product line are IGES, STEP, STL, VDA-FS and VRML.
Unigraphics										STEP, JT
+ Notes: Supported file formats from the Unigraphics product line are IGES, Parasolids, STEP, STL and VDA-FS. However, the Okino IGES importer has always worked well, and has been specifically tweaked, for importing IGES files exported from Unigraphics.

Legend: = preferred import method. , and are the second, third and fourth preferred import methods.