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How to convert STEP (.step,.stp) 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.

STEP

STEP is the defacto 'go-to' MCAD translation file format when you do not have access to the original CAD part and assembly files. It is a long standing 'industry standard' that can be used to move MCAD/CAD file assets into many downstream 3D programs and file formats. Okino's PolyTrans|CAD provides for a defacto 3D STEP file conversion solution used by the world's primary & professional engineering, aerospace, military, corporate, animation/multi-media and VR/AR industries. STEP uses the .stp and .step file extensions.

STEP files are readable ASCII files which encode CAD parts and assembly information. Most respectable MCAD modellers will actively and correctly support the STEP AP203 and AP214 file formats. STEP was originally developed to supercede the IGES file format but has mostly supplemented but not replaced IGES. You would either want to export a "STEP AP214" file or an "IGES BREP solids" file depending on the MCAD modeller.

A much deeper overview plus explanation of STEP, and how it can be best used + understood, is outlined in this Okino WEB page.

Most people initially come to Okino asking for a STEP importer but it should only be used in specific situations as outlined in our "CAD Data Sourcing Suggestons and Rules".

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 STEP

STEP import converter's overview

DGN export converter's overview