Home > Supported File Formats > IGES to DWG

How to convert IGES (.igs) to DWG (AutoCAD, DXF)?

PolyTrans|CAD+DCC performs mathematically precise CAD, DCC/Animation, GIS and BIM 3D file conversions into all key downstream 3D packages and file formats. Okino software is used and trusted throughout the world by many tens of thousands of 3D professionals in mission & production critical environments, backed by respectable personal support directly from our core development team.

IGES

IGES was the defacto 'go-to' MCAD translation file format but has long since been overtaken by the STEP file format. IGES and STEP are equally good file formats to translate CAD and MCAD model data files but it all depends on how well the files are exported from the corresponding MCAD modeller software.

As an ANSI standard since 1980, IGES has been used in the automotive, aerospace, and shipbuilding industries. Version 5.3 (1996) is the last published and stable standard of IGES. IGES is one of the original CAD vendor-neutral 3D data translation file formats which was designed for high fidelity data exchange between all major professional 3D modelling applications. IGES uses the .igs and .iges file extensions.

Okino's PolyTrans|CAD provides for a defacto 3D IGES file conversion solution used by the world's primary & professional engineering, aerospace, military, corporate, animation/multi-media and VR/AR industries.

A much deeper overview plus explanation of IGES, and how it can be best used + understood, is outlined in this Okino WEB page. It is vitally important to understand the differences between "old school" and "new school" IGES files, as this is little understood by most 3D graphics users.

DWG

DXF and DWG are the native file formats of the Autodesk AutoCAD product since 1982. DWG is the binary file variation to the ASCII DXF file format. These files can be viewed by many programs including Autodesk's free DWG TrueView application. It is a closed file format but has been documented by the Open Design Alliance.

At Okino we consider DXF/DWG to be one of the worst 3D file formats when translating 3D model data between applications (depending on its contents). There is very little understanding about this in the 3D graphics world. As outlined in our "CAD Data Sourcing Suggestons and Rules" page you should ideally use the DWF-3D file format when sourcing from either AutoCAD, Navisworks, Revit and optionally Autodesk Inventor.

Due to deep history, Autodesk software can embed ACIS SAT "BREP solids" data in some of its DXF/DWG files. This is the ideal case as the "BREP solids" geometry definitions lead to cleaner and higher fidelity MCAD file conversions. But even so, it would generally be a safer bet to use a STEP AP214 or "IGES BREP solids" file in such cases.

More information about IGES

IGES import converter's overview

DWG export converter's overview