Common File Types for 3D CAD Software

Different modules of software support different CAD file formats. For example, in Pro Engineer, part module supports .prt, assembly module supports .asm file formats and so on. The scope of these discussions to the different CAD files formats used by Pro Engineer, SolidEdge and AutoCAD. The neutral CAD file formats used to exchange data between different CAD software will also be included to the scope of discussion.

CAD file formats supported by AutoCAD: AutoCAD is used mainly for 2D drafting, however 3D is also possible in AutoCAD. All AutoCAD drawing is by default saved in .dwg file format. However there are various tools available within AutoCAD by which drawing could be exported/converted/saved as to other 2D CAD file formats such as:

• • .DWF
  • .DXF
  • .ACIS
  • .BMP

• How to use AutoCAD for creating file of DWF file format?

DWF stands for drawing web format. For creating DWF file format, one need to go to file>plot, in the plot device tab of it DWF eplot plotter need to be selected and after that file name and location need to be specified. The DWF file will be created at the specified location, once the OK button is pressed. DWF file format is suitable for web publishing of drawing.

• How to create file of DXF file format?

DXF is a text file, which contains all the necessary information of the drawing. DXF file is readable by most of the other CAD system or software. In other word DXF is a neutral 2D CAD file format. For creating DXF file, one need to do save as and change the save as type to DXF.

• How to create file of ACIS file format?

One need to go to file>export, the save as type options need to be changed to ACIS. Then by hitting the save button and selecting the objects of the drawing to be saved in this file format, the ACIS file will be generated.

• How to create file of BMP file format?

BMP file can be created by exporting the drawing and changing the save as type to bitmap.

• CAD file formats supported by Pro Engineer: Different modules of pro engineer supports/use different file formats. For example, part files of pro engineer are having .prt file format and assembly files are having .asm file format. Pro engineer files can be exported to some other file format as well, the important of these are:
  • • IGES
    • STEP

• How to create IGES or STEP file using pro engineer?

For exporting files from pro engineer, one need to use the file>save a copy option and select the type to suitable file format (like, IGES, STEP etc.). Of course before that correct folder location and file name needs to be given.

• CAD file formats supported by solid edge: Opened solid edge model could be exported to file of other file formats by file>save as. Solid edge also supports a lots of CAD file formats to export, most important of them are:
  • • IGES
    • STEP

So, it has been seen that exporting files are almost similar for most of the CAD programs and most useful neutral formats are IGES and STEP. Before taking a decision on exporting CAD files, selection of suitable file format among the two is important in order to get desired results in exported CAD files. The following discussion will be helpful on this.

• IGES: IGES stands for initial graphics exchange specification. IGES was started by a group of CAD users and vendors, like Boeing, General electric, Xerox etc., with support from National bureau of standards (NIST) and U.S Department of Defense (DoD). Intention was to create a neutral data file format for exchanging CAD data across various CAD software.

Extension for IGES file format is .igs.

• STEP: STEP stands for Standard for The Exchange of Product model data. STEP file format is covered under ISO 10303. The aim of developing STEP file format is to provide a mechanism, which is capable to describe product data throughout the life cycle of a product, independent of any particular CAD/CAM/PDM/PLM system. Though the scope of STEP file format is much wider than IGES, but still STEP is unable to replace IGES completely.

Extension for STEP file format is .stp.

• IGES vs. STEP: IGES file format initially supported only basic drawing entities like line, polylines etc., and the support extended up to B-rep and CSG in the later versions of it. IGES file format is good for exporting 2D CAD drawings and 3D surface models. 3D solid models are exported as sets of surfaces (and then need to be healed and/or closed when imported).

STEP file format, on the other hand, is good for 3D solid models. STEP file format is capable of handling geometric as well as non-geometric data. STEP is relatively somewhat more useful for PDM/PPM. Exchanging 2D CAD drawings using STEP file format is still not supported by most of the CAD vendors.