# how to read STEP file in vtk wasm

**URL:** https://discourse.vtk.org/t/how-to-read-step-file-in-vtk-wasm/16128
**Category:** Web
**Tags:** vtkwasm
**Created:** [November 7, 2025, 8:03am UTC](https://discourse.vtk.org/t/how-to-read-step-file-in-vtk-wasm/16128 "2025-11-07T08:03:04Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![blocky](https://discourse.vtk.org/user_avatar/discourse.vtk.org/blocky/32/9531_2.png) [@blocky](https://discourse.vtk.org/u/blocky)
#### Post date: [November 7, 2025, 8:03am UTC](https://discourse.vtk.org/t/how-to-read-step-file-in-vtk-wasm/16128/1 "2025-11-07T08:03:04Z")

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Hi everyone,

I’m currently trying to read STEP files in VTK WASM. Based on some previous posts, I recompiled the vtk-master version, set `VTK_MODULE_ENABLE_VTK_IOOCCT` to YES, and compiled a 32-bit version of OpenCASCADE (my WASM is also 32-bit). I pointed the OpenCASCADE\_DIR to the folder with the compiled files.

During the VTK-master compilation, I encountered the following warning:

```bash
CMake Warning (dev) at D:/OpenCASCADE/OCCT-7_9_2_build/OpenCASCADEFoundationClassesTargets.cmake:57 (add_library):
  ADD_LIBRARY called with SHARED option but the target platform does not
  support dynamic linking. Building a STATIC library instead. This may lead
  to problems.
Call Stack (most recent call first):
  D:/OpenCASCADE/OCCT-7_9_2_build/OpenCASCADEConfig.cmake:100 (include)
  CMake/vtkModule.cmake:5394 (find_package)
  IO/OCCT/CMakeLists.txt:1 (vtk_module_find_package)
This warning is for project developers. Use -Wno-dev to suppress it.

```

However, the compilation was successful in the end. When I used the compiled VTK to compile my C++ code, I encountered the following error:

```bash
wasm-ld: error: unknown file type: D:/OpenCASCADE/win32/vc14/bin/TKDESTEP.dll

```

I suspect this might be related to dynamic linking, so I tried recompiling VTK with `BUILD_SHARED_LIBS` enabled, but there was no change—the two errors still occur.

When I do not use IOOCCT, I can compile other C++ files without any issues. This process was performed on a Windows 10 system.

Could anyone point out what might be missing in my configuration or steps? Any guidance would be much appreciated!

---

<div class="post-metadata">

### Author: ![finetjul](https://discourse.vtk.org/user_avatar/discourse.vtk.org/finetjul/32/154_2.png) [@finetjul](https://discourse.vtk.org/u/finetjul)
#### Post date: [January 30, 2026, 3:33pm UTC](https://discourse.vtk.org/t/how-to-read-step-file-in-vtk-wasm/16128/2 "2026-01-30T15:33:00Z")

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Why don’t you want to build with STATIC linking ?