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3D STEP File Importer, Converter and Translator

Arrow Importing and Converting from 3D STEP CAD Files

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

Okino came to pioneer the MCAD conversion market over the last 30+ years and as such our STEP import solution has been designed to handle super-ultra-massive datasets that would otherwise choke and drag other conversion solutions to their knees. Okino software is well known, and sold specifically, for its ability to handle STEP files from the very smallest to the very largest in a rock solid and robust + efficient manner.

CP3 Scooter Concept Image. Converted via Okino's PolyTrans|CAD System.
Artist: Christoph Bodensieck, Industrial PDD & Switch Mobility.
Click on image to see full scale rendition.

Arrow More Information About the Okino STEP Converter?

Technical details about Okino's STEP importer can be read here.

Okino also recommends that you import your CAD files via these native importers (among others):

Autodesk Inventor




Rhino 3D

Solid Edge


Arrow What is the 'STEP' 3D File Format?

STEP AP203/AP214 is the main CAD vendor-neutral 3D data translation file format which was designed for high fidelity data exchange between all major professional 3D modelling applications. It was evolved as a successor to the IGES vendor-neutral file format but today you will find STEP and IGES data files coexisting with each other.

If you do not have access to the original native CAD files then STEP would be the best file format to request from your data vendor, or a properly exported "IGES BREP Solids" file. You will want to ask for such STEP files to be exported as 'BREP solids' (and not 'Surfaces') and in the STEP AP214 variation.

STEP (or 'ISO standard 10303') is actually a massive and deeply complex set of specifications which define data exchange standards for a wide range of industries and applications. Each are defined, maintained and ratified by various ISO technical committees.

STEP files from the CAD and MCAD industry will typically contain these fundamental elements and structures:

  1. NURBS analytic/parametric geometry
  2. NURBS/bicubic curves & 3D polylines
  3. 'BREP' topology information (to define 'solids' geometry)
  4. CAD assembly hierarchy and structure
  5. Geometry instancing
  6. Part naming
  7. Meta data
  8. Unit-of-measure, geometric tolerance and other cursory source-modeller information
  9. And basic materials.

Arrow How Can I Determine From Which MCAD Program a 3D STEP File Came From?

The very first question that we ask of our new customers is 'From which MCAD program is your STEP file coming from?'. That can be very important information, depending on the name of the source MCAD program.

STEP files are easily read ASCII text files that can be opened in any general text editor. After opening the file in such a text editor you will want to look for the text labelled 'FILE_NAME' close to the start of the file. The name of the originating MCAD program will usually be defined within that sub-section. The following are some typical examples:

FILE_NAME ('FILENAME.STEP', 'T08:28:23', ("), ("), 'SwSTEP 2.0', 'SolidWorks', ''); FILE_NAME('FILENAME.stp', 'T02:22:23',("),(''), 'Inventor,'Autodesk Inventor',''); FILE_NAME('FILENAME', 'T23:57:22',("),(''), 'PTC','CREO PARAMETRIC',''); FILE_NAME( /* name */ 'FILENAME', /* time_stamp */ 'T18:05:02+01:00', /* author */ ('My Name'), /* organization */ ('Company Name'), /* preprocessor_version */ 'ST-DEVELOPER v10', /* originating_system */ 'UGS - NX', /* authorisation */ '');

Arrow Common Destinations of 3D STEP Files With Okino Software

Okino's PolyTrans|CAD imports, optimizes and intelligently converts STEP files into all major 3D file formats, animation packages, military VisSim, virtual reality (VR) and augmented reality (AR) systems (such as Unity and Unreal Engine), and third party/OEM integrations.

STEP part and assembly files can be effortlessly and directly converted into such popular & common destinations such as:

  1. STEP (.step, .stp) to AutoCAD (.dwg, .dxf)
  2. STEP (.step, .stp) to 3ds Max (.max)
  3. STEP (.step, .stp) to CADMATIC (.3dp)
  4. STEP (.step, .stp) to CINEMA 4D (.c4d)
  5. STEP (.step, .stp) to COLLADA (.dae)
  6. STEP (.step, .stp) to DWF-3D (.dwf)
  7. STEP (.step, .stp) to FBX (for Unity, Unreal and MODO)
  8. STEP (.step, .stp) to JT Open (.jt)
  9. STEP (.step, .stp) to LightWave (.lws, .lwo)
  10. STEP (.step, .stp) to Maya (.mb)
  11. STEP (.step, .stp) to Microstation DGN (.dgn)
  12. STEP (.step, .stp) to OpenFlight (.flt)
  13. STEP (.step, .stp) to NGRAIN 3KO (.3KO)
  14. STEP (.step, .stp) to Rhino-3D (.3dm)
  15. STEP (.step, .stp) to SketchUp (.skp)
  16. STEP (.step, .stp) to STL (.stl)
  17. STEP (.step, .stp) to Visual Components
  18. STEP (.step, .stp) to Acrobat-3D (PDF via U3D) (.u3d)
  19. STEP (.step, .stp) to VRML2 & X3D (.wrl, .x3d)
  20. STEP (.step, .stp) to Wavefront (.obj)
  21. STEP (.step, .stp) to dozens more 3D file formats


Kemppi Welding Machines, STEP to LightWave, by Spikey Animation and Kemppi Oy. See explanation here.