# How to Open Step File in VTK

**URL:** <https://discourse.vtk.org/t/how-to-open-step-file-in-vtk/703>\
**Category:** Support\
**Created:** [April 8, 2019, 9:39am UTC](https://discourse.vtk.org/t/how-to-open-step-file-in-vtk/703 "2019-04-08T09:39:49Z")\
**Posts on this page:** 11\
**Page:** 1

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**Author:** ![lbhking](https://discourse.vtk.org/letter_avatar_proxy/v4/letter/l/b19c9b/32.png) [@lbhking](https://discourse.vtk.org/u/lbhking)\
**Post date:** [April 8, 2019, 9:39am UTC](https://discourse.vtk.org/t/how-to-open-step-file-in-vtk/703/1 "2019-04-08T09:39:49Z")

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Who can tell me how to open the STEP file and display it? Thank you!

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**Author:** ![sergey.slyadnev](https://discourse.vtk.org/user_avatar/discourse.vtk.org/sergey.slyadnev/32/291_2.png) [@sergey.slyadnev](https://discourse.vtk.org/u/sergey.slyadnev)\
**Post date:** [April 9, 2019, 8:26am UTC](https://discourse.vtk.org/t/how-to-open-step-file-in-vtk/703/2 "2019-04-09T08:26:16Z")

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You may read the STEP file with OpenCascade kernel and then visualize it in a VTK scene after faceting (generating visualization mesh from a CAD model). Here is the project where this workflow is readily available: [https://gitlab.com/ssv/AnalysisSitus](https://gitlab.com/ssv/AnalysisSitus)

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**Author:** ![lbhking](https://discourse.vtk.org/letter_avatar_proxy/v4/letter/l/b19c9b/32.png) [@lbhking](https://discourse.vtk.org/u/lbhking)\
**Post date:** [April 11, 2019, 8:28am UTC](https://discourse.vtk.org/t/how-to-open-step-file-in-vtk/703/3 "2019-04-11T08:28:31Z")

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thank you Quaoar!

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**Author:** ![mwestphal](https://discourse.vtk.org/user_avatar/discourse.vtk.org/mwestphal/32/19_2.png) [@mwestphal](https://discourse.vtk.org/u/mwestphal)\
**Post date:** [March 8, 2024, 8:40am UTC](https://discourse.vtk.org/t/how-to-open-step-file-in-vtk/703/4 "2024-03-08T08:40:07Z")

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There is now a vtkOCCTReader in VTK able to read step files.

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**Author:** ![wxfred](https://discourse.vtk.org/user_avatar/discourse.vtk.org/wxfred/32/9691_2.png) [@wxfred](https://discourse.vtk.org/u/wxfred)\
**Post date:** [January 8, 2025, 8:59am UTC](https://discourse.vtk.org/t/how-to-open-step-file-in-vtk/703/5 "2025-01-08T08:59:27Z")

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I can’t find any document about vtkOCCTReader in python,  
`from vtkmodules.vtkIOLegacy import vtkOCCTReader`  
comes with

```auto
from vtkmodules.vtkIOLegacy import vtkOCCTReader
ImportError: cannot import name 'vtkOCCTReader' from 'vtkmodules.vtkIOLegacy'

```

Is there any python example?

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**Author:** ![mwestphal](https://discourse.vtk.org/user_avatar/discourse.vtk.org/mwestphal/32/19_2.png) [@mwestphal](https://discourse.vtk.org/u/mwestphal)\
**Post date:** [January 8, 2025, 9:00am UTC](https://discourse.vtk.org/t/how-to-open-step-file-in-vtk/703/6 "2025-01-08T09:00:00Z")

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Which version of VTK are you using ?  
How did you install it ?

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**Author:** ![wxfred](https://discourse.vtk.org/user_avatar/discourse.vtk.org/wxfred/32/9691_2.png) [@wxfred](https://discourse.vtk.org/u/wxfred)\
**Post date:** [January 8, 2025, 9:02am UTC](https://discourse.vtk.org/t/how-to-open-step-file-in-vtk/703/7 "2025-01-08T09:02:34Z")

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vtk = “^9.4.1”  
I installed it with poetry, and I can run the example 01\_vtk\solution\_flow.py successfully.  
I just want to change some code to test STEP loading.

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**Author:** ![mwestphal](https://discourse.vtk.org/user_avatar/discourse.vtk.org/mwestphal/32/19_2.png) [@mwestphal](https://discourse.vtk.org/u/mwestphal)\
**Post date:** [January 8, 2025, 1:35pm UTC](https://discourse.vtk.org/t/how-to-open-step-file-in-vtk/703/8 "2025-01-08T13:35:28Z")

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Then it means OCCT is not enabled in the python wheels. You need to build open cascade and VTK yourself to access it.

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**Author:** ![wxfred](https://discourse.vtk.org/user_avatar/discourse.vtk.org/wxfred/32/9691_2.png) [@wxfred](https://discourse.vtk.org/u/wxfred)\
**Post date:** [January 9, 2025, 1:14pm UTC](https://discourse.vtk.org/t/how-to-open-step-file-in-vtk/703/9 "2025-01-09T13:14:10Z")

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Thanks for reply. How can I check whether vtkXXXReader is support in python? Maybe it is in another package, not `from vtkmodules.vtkIOLegacy`. Is there any document for python wheel?

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**Author:** ![mwestphal](https://discourse.vtk.org/user_avatar/discourse.vtk.org/mwestphal/32/19_2.png) [@mwestphal](https://discourse.vtk.org/u/mwestphal)\
**Post date:** [January 9, 2025, 1:16pm UTC](https://discourse.vtk.org/t/how-to-open-step-file-in-vtk/703/10 "2025-01-09T13:16:24Z")

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The configuration is here: [https://gitlab.kitware.com/vtk/vtk/-/blob/master/.gitlab/ci/configure\_wheel.cmake?ref\_type=heads](https://gitlab.kitware.com/vtk/vtk/-/blob/master/.gitlab/ci/configure_wheel.cmake?ref_type=heads)

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**Author:** ![EthanTan](https://discourse.vtk.org/user_avatar/discourse.vtk.org/ethantan/32/10801_2.png) [@EthanTan](https://discourse.vtk.org/u/EthanTan)\
**Post date:** [October 27, 2026, 3:47am UTC](https://discourse.vtk.org/t/how-to-open-step-file-in-vtk/703/11 "2026-10-27T03:47:59Z")

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Soft tip if you only need to inspect the STEP before wiring OpenCascade→VTK: a browser STEP viewer can confirm the model first. I’m Ethan Tan, CTO of CADProps — free STEP viewer (~92 formats). [STEP Viewer Online: Open STP Files & Measure CAD | CADProps](https://www.cadprops.com/tools/step-viewer/)