No instructions for running the new Viewer on Windows 11

[joshstavva]

I try running QIFCViewer.py but it seems to depend on Pyside2, which doesnt seem to be available in latest versions of python. Is this best ran after installing Qt? What are the dependency requirements?

[stefkeB]

I've had mixed experiences with the different variants of Qt with Python. In general, the code works fine with PyQt5 and while largely equivalent to PySide, PyQt6 and PySide2 made some changes to the creation of 3D geometry, which I haven't been able to resolve yet.

Alas, the code is not entirely portable between these libraries. E.g. since Qt6, some Qt3d classes have moved between Qt3DCore and Qt3DRender! QBuffer, QAttribute and QGeometry moved to Qt3dCore. The Qt3d libraries are pretty sensitive when setting up a custom geometry rendering pipeline. I was able to get rid of all errors, but nothing shows up.

So in general, I work from PyQt5 and PyQt3D instead of PySide.
pip install pyqt5
pip install pyqt3d

To make things even more complicated, the use of the OCC libraries requires a careful install of the equivalent and compatible versions of opencascade and OCC (the Python wrappers).

[mayor686]

I had the same issues, particularly the geometry not appearing with PySide2. I had to install Conda to be able to install OpenCascade. Could you add some more information in the README file to get the code working? Thanks.

[stefkeB]

I'm porting the code to Qt6 in the following branch #3
I have a few test fragments laying around which seem to work in Qt6, but the code is not compatible with Qt5, alas.

Last week I played with an alternative setup, using Xeokit as a Javascript-based viewer inside an embedded browser view. It is more cumbersome to talk back and forth between Python and JavaScript, but I got a working basic example. But it also does a double conversion: ifc to geometry in Javascript and Ifc to properties & other data in Python.

[stefkeB]

The Qt6 update is progressing. With PySide6 and with disabled dependency on the OCC package (pythonocc-core) I could restore the 3D view, with a large part of the interface.

Picking is not resolved yet and the QTO does not list all attributes yet.

I couldn't get the whole Python + Ifcopenshell setup installed in Windows 11 (somehow conda installed OCC, but not ifcopenshell, as it relies on a math library which has to be compiled from C++ code...). Frustrating, as these packages are in constant flux right now.

[stefkeB]

After having installed the Visual Studio Build tools and the C++ Development SDK (all from the build tools installer), I could compiled Mathutils (from the Blender Package), which was the remaining ifcopenshell dependency.

In this Qt6 branch, I've fixed most of the viewer, so it doesn't rely on OCC python package anymore. Now I could run the Viewer again on Windows. There are some remaining issues, but at least I could confirm that loading an IFC, generating 3D geometry and all properties was restored.