Freecad updates break Optics Workbench opbjects?

[salmansamson]

Hello Dr Bergmann, and thanks for the reply on the forum thread.

Regarding our open source cytometer project which is using your excellent Optics Workbench, the issue seems to be that saving the Freecad FCStd file without the Optics Workbench properly installed breaks the objects within it. Then when the Optics Workbench is installed again, there is no way to recover these objects. This is easy to do: sometimes, at least for me, the Freecad installation breaks and has to be reinstalled, or a collaborator edits the file in Freecad without the Optics Workbench installed. Is it possible to make it so that Freecad without the Optics WB does not break these objects and if the Optics WB is reinstalled that these objects work again?

Examples here:

1. when everything was ok

2. rays have broken

3. lenses etc also broken

[salmansamson]

Actually, there appear to be two issues here. One is as described. However, another is that all the ray objects spontaneously break for me in the latest version of Freecad 1.1.1, i.e. if I open a file last saved in a previous version and recompute, the all rays give the error message "FeaturePython object has no attribute RadiationPattern".

[chbergmann]

Thank you for reporting the issues. I was able to fix a backwards compatiblity issue with missing features like RadiationPattern. Please update the Optics workbench.
If the Optics workbench is not installed, you cannot use Optics workbench features. There is no way to fix this.

[salmansamson]

Thanks for the fast response! I updated the workbench. But unfortunately the rays still break: when loading the example above ("when everything was ok" / 5jun), then recalculating the ray tracing, then all rays give that error message again.

(Regarding the other issue, I don't mean that I want to use any Optics Workbench features without the WB installed. But I don't want Freecad to break the optics objects if I or collaborators edit the FCStd file without the WB installed. If this is hard to prevent in the code, I guess we can just manage editing better.)

Snippet of error message:

Beam: 'FeaturePython' object has no attribute 'RadiationPattern'
Traceback (most recent call last):
File "/home/ssr/.local/share/FreeCAD/v1-1/Mod/OpticsWorkbench/./Ray.py", line 165, in execute
self.redrawRay(fp)
File "/home/ssr/.local/share/FreeCAD/v1-1/Mod/OpticsWorkbench/./Ray.py", line 308, in redrawRay
main_dir = Vector(1, 0, 0) if fp.RadiationPattern == 'dipole' else Vector(0, 0, 1)
^^^^^^^^^^^^^^^^^^^
<class 'AttributeError'>: 'FeaturePython' object has no attribute 'RadiationPattern'
Traceback (most recent call last):
File "/home/ssr/.local/share/FreeCAD/v1-1/Mod/OpticsWorkbench/./Ray.py", line 165, in execute
self.redrawRay(fp)
File "/home/ssr/.local/share/FreeCAD/v1-1/Mod/OpticsWorkbench/./Ray.py", line 308, in redrawRay
main_dir = Vector(1, 0, 0) if fp.RadiationPattern == 'dipole' else Vector(0, 0, 1)
^^^^^^^^^^^^^^^^^^^
<class 'AttributeError'>: 'FeaturePython' object has no attribute 'RadiationPattern'
Traceback (most recent call last):
File "/home/ssr/.local/share/FreeCAD/v1-1/Mod/OpticsWorkbench/./Ray.py", line 165, in execute
self.redrawRay(fp)
File "/home/ssr/.local/share/FreeCAD/v1-1/Mod/OpticsWorkbench/./Ray.py", line 308, in redrawRay
main_dir = Vector(1, 0, 0) if fp.RadiationPattern == 'dipole' else Vector(0, 0, 1)
^^^^^^^^^^^^^^^^^^^

[chbergmann]

Please check the version of the Optics workbench. It should be 1.3.8. If still 'FeaturePython' object has no attribute xxx error occur if you load an older project this version, can you share your design ?

[chbergmann]

I tried to open an Optics design without the Optics workbench installed. We are getting these errors:
07:40:33 PropertyPythonObject::Restore: blocked import of module 'OpticalObject' during document restore. Only modules from FreeCAD or installed addons are permitted.
07:40:33 pyException: (1)<class 'ImportError'>: module not permitted: OpticalObject
07:40:33 PropertyPythonObject::Restore: blocked import of module 'Ray' during document restore. Only modules from FreeCAD or installed addons are permitted.
07:40:33 pyException: (1)<class 'ImportError'>: module not permitted: Ray

I fear this issue cannot be fixed.

[salmansamson]

Yes, I'm afraid the rays definitely still break. It is version 1.3.8 in the Add-Ons Manager (updated 28/7/26). The FCStd is linked above (on Github): https://github.com/Cytkit/cytkit/blob/v0.8_dev/CAD%20and%20optical%20model/main%20body%20with%20optics%20-%205jun%20optics%20all%20ok.FCStd

[chbergmann]

I cannot open any of your designs.
<class 'OSError'>: Invalid project file /home/christi/Downloads/freecad/main body with optics - 5jun optics all ok.fcstd: basic_ios::clear: iostream error
Which other workbenches must be installed ?
Which FreeCAD version are you using ?

[salmansamson]

Oh dear, sorry to hear that! I can't think of any explanation. I confirm that I am opening them without any other workbenches installed except the Optics Workbench. Freecad version is 1.1.1 (the AppImage on Linux): FreeCAD_1.1.1-Linux-x86_64-py311.AppImage