Home > Supported File Formats > IGES to DGN

How to convert IGES (.igs) to DGN (MicroStation)?

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.

DGN

DGN is a 2D/3D file format, with its roots going back to the early 1980s, that is used as the native file format of such programs as Bentley's MicroStation and Intergraph's PDS software packages. Relative to deep history, DGN could be considered a competitor or rival to the Autodesk DWG file format. Okino considers both DGN and DWG rather "crude" and old file formats, depending on what vintage of file is used and whether the files contain ACIS-SAT/Parasolid "BREP solids" geometry or just 2D/3D vector geometry.

Okino considers a DGN V8 file to be of two varieties: (1) "GIS" like models defined using basic primitives like lines, curves, arcs and 3D objects defined by the extrusion and revolution of these basic elements - these types of files are typically glutted with an enormous number of basic elements which can result in massive scenes that can very slow to display and take up a lot of memory. (2) The second variety of DGN file uses the more modern "BREP solids" geometry type to define the 3D objects as lighter weight and more efficient NURBS surfaces and solids.

Okino spent over 20 years developing its DGN importers and exporters. As such, we understand the nuances of DGN and its related conversion issues. Please refer to our DGN importer WEB page which has extensive information on (1) the history of DGN and when to use DGN, (2) how to import massive DGN files (such as PDMS 3D plants, oil refineries, etc), (3) how to import from AVEVA PDMS and Intergraph PDS, and (4) our suggestions about using STEP or VRML2 as alternative conversion methods from Bentley's MicroStation.

More information about IGES

IGES import converter's overview

DGN export converter's overview