Group data gets lost if a FemMesh is assigned to a new document object

[bernd]

If a FemMesh with groups is assingned to a new document object from type FemMeshObject the group data is lost in space ... Attached a file and the code.

cheers bernd

GroupMeshProblems.FCStd

(15.32 KiB) Downloaded 13 times

the code:

Code: Select all

obj1 = App.ActiveDocument.getObject("mesh_with_groups")
obj1.FemMesh.GroupCount

msh1 = obj1.FemMesh
msh1.GroupCount

obj2 = App.ActiveDocument.addObject("Fem::FemMeshObject","new_mesh_with_groups")
obj2.FemMesh = obj1.FemMesh
obj2.FemMesh.GroupCount

output:

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>>> obj1 = App.ActiveDocument.getObject("mesh_with_groups")
>>> obj1.FemMesh.GroupCount
10
>>> 
>>> msh1 = obj1.FemMesh
>>> msh1.GroupCount
10
>>> 
>>> obj2 = App.ActiveDocument.addObject("Fem::FemMeshObject","new_mesh_with_groups")
>>> obj2.FemMesh = obj1.FemMesh
>>> obj2.FemMesh.GroupCount
0
>>> 

FreeCAD version

Code: Select all

OS: Windows 7
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.17.8796 (Git)
Build type: Release
Branch: master
Hash: e5045f72e954ec295318f5271e9ffddd95b73847
Python version: 2.7.8
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 7.0.0

[yorik]

Yes all the python groups are currently not working after last extensions merge... ickby, that's your turn now

[bernd]

Yes all the python groups are currently not working after last extensions merge... ickby, that's your turn now

No it's not this. The groups I'm talking about are not FreeCAD groups. The lost groups are SMESH groups.

[wmayer]

I would say it's simply not implemented in https://github.com/FreeCAD/FreeCAD/blob ... h.cpp#L112
Unfortunately the smesh classes don't offer a method to assign data to a new instance. So, we have to do this all on our own.

[wmayer]

git commit a812ad2

[bernd]

git commit a812ad2

works great

[bernd]

I'm facing the next problem ... I added a python object to the Fem::FemMeshObject. See https://github.com/berndhahnebach/FreeC ... fa61fee064

My new python mesh object works great so far except the ViewProvider. The defs from the FemGui::ViewProviderFemMesh are missing in the FemGui::ViewProviderFemMeshPython.

code:

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mesh = App.ActiveDocument.getObject("Box_mesh")
mesh.TypeId
mesh.ViewObject.TypeId
mesh.ViewObject.setNodeColorByScalars()

mesh_python = App.ActiveDocument.getObject("Box_Mesh")
mesh_python.TypeId
mesh_python.ViewObject.TypeId
mesh_python.ViewObject.setNodeColorByScalars()

output:

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>>> mesh = App.ActiveDocument.getObject("Box_mesh")
>>> mesh.TypeId
'Fem::FemMeshObject'
>>> mesh.ViewObject.TypeId
'FemGui::ViewProviderFemMesh'
>>> mesh.ViewObject.setNodeColorByScalars()
>>> 
>>> mesh_python = App.ActiveDocument.getObject("Box_Mesh")
>>> mesh_python.TypeId
'Fem::FemMeshObjectPython'
>>> mesh_python.ViewObject.TypeId
'FemGui::ViewProviderFemMeshPython'
>>> mesh_python.ViewObject.setNodeColorByScalars()
Traceback (most recent call last):
  File "<input>", line 1, in <module>
AttributeError: 'Gui.ViewProviderPythonFeature' object has no attribute 'setNodeColorByScalars'
>>> 

mesh--mesh_python.fcstd

(35.73 KiB) Downloaded 15 times

[bernd]

I copied the code for the FemMeshObjectPython from FemSolverObjectPython. If I try to add a simple object I get a grey ViewProvider. On solver object python I get a coloured ViewProvider.

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obj1 = FreeCAD.ActiveDocument.addObject("Fem::FemMeshObjectPython", "test1")
obj2 = FreeCAD.ActiveDocument.addObject("Fem::FemMeshObject", "test2")

obj3 = FreeCAD.ActiveDocument.addObject("Fem::FemSolverObjectPython", "test3")
obj4 = FreeCAD.ActiveDocument.addObject("Fem::FemSolverObject", "test4")

mesh_vs_solver.fcstd

(2.52 KiB) Downloaded 16 times

screen.jpg (30.59 KiB) Viewed 1215 times

[bernd]

The defs I'm missing are implemented in ViewProviderFemMeshPyImp.cpp https://github.com/FreeCAD/FreeCAD/blob ... hPyImp.cpp How this is connected to ViewProviderFemMesh and my new PythonFeatureViewProvider ... I'm lost in space of C++

[wmayer]

In App we have two key classes:
The template class FeaturePythonT which implements the methods to hold a Python class that implements the Feature interface
The template class FeaturePythonPyT which implements the methods addProperty, removeProperty and supportedProperties to be used from Python side. You can extend your actual Python binding class by sub-classing

In Gui we have these two classes:
The template class ViewProviderPythonFeatureT is the counterpart of FeaturePythonT and implements the interface for view providers
The class ViewProviderPythonFeaturePy. This does serve the same purpose as FeaturePythonPyT but is not a template class. This way it's not easily possible at the moment to have a Python interface that implements the logic for Python view providers _and_ offer the methods addProperty, removeProperty and supportedProperties.

I think I should simplify the framework somewhat.