@Pl45m4 only one thing: which project type should I create in Visual Studio? Qt Designer custom widget? do we need to export the widget?

__declspec(dllexport)??

The only problem is the examples are for use in Qt Creator I think while I am in Visual Studio... is there a VS example?
How can I find the value of the macros like $$[QT_INSTALL_PLUGINS] and ${INSTALL_EXAMPLEDIR}?

@Pl45m4 Thanks!

After building the VTK using Qt5.13.2, I uninstalled the Qt version since I already have 5.12.6. While running a sample code to check the VTK plugin I m getting the following linker error:

09:49:20: Running steps for project pcl_visualizer... 09:49:20: Starting: "/usr/bin/cmake" --build . --target all [ 20%] Automatic MOC and UIC for target pcl_visualizer [ 20%] Built target pcl_visualizer_autogen [ 40%] Linking CXX executable pcl_visualizer /usr/bin/ld: /usr/local/lib/libvtkGUISupportQt-7.1.so.1: undefined reference to `qt_version_tag@Qt_5.13' collect2: error: ld returned 1 exit status make[2]: *** [CMakeFiles/pcl_visualizer.dir/build.make:254: pcl_visualizer] Error 1 make[1]: *** [CMakeFiles/Makefile2:77: CMakeFiles/pcl_visualizer.dir/all] Error 2 make: *** [Makefile:84: all] Error 2 09:49:21: The process "/usr/bin/cmake" exited with code 2. Error while building/deploying project pcl_visualizer (kit: Desktop Qt 5.12.6 GCC 64bit) When executing step "CMake Build" 09:49:21: Elapsed time: 00:01.

I m using CMake system and I tried the solution given here but it is not working.
Should I create a different thread for this?

Hello @Andreas-Schacherbauer ,

did you find out any solution?

@anp405, my first guess would be that by setting PYTHONPATH you are losing the location of PyQt5 package. This depends on your Python and environment setup, but if there is some PYTHONPATH existing, you are overriding it completely instead of complementing. You can verify this by opening a new command line session, setting PYTHONPATH to wherever your code sets it, then running Python interpreter and trying to import PyQt5.

Another guess would be that your child process uses different Python environment (e.g. built-in system Python 2), which does not have PyQt5 installed in its site-packages.