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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='color:#1F497D'>Although I am still interested in a better solution, I currently have found following way to deal with this:<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>I wrote a function, which creates a boost::python::object from the vtkUnstructuredGrid, which it obtains from my MyClass object:<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>#include <vtkPythonUtil.h><o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>using boost::python::object;<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>using boost::python::import;<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>boost::python::object GetGrid(MyClass *m)<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>{<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='color:#1F497D'> object vtk_module = import("vtk");<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='color:#1F497D'> vtkUnstructuredGrid *volume = m->GetVolume();<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='color:#1F497D'> if(volume==NULL) return object(boost::python::handle<>(Py_None));<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='color:#1F497D'> boost::python::handle<> pvolume(vtkPythonGetObjectFromPointer((vtkObjectBase *)volume));<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='color:#1F497D'> return object(pvolume);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='color:#1F497D'>}<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> vtkusers-bounces@vtk.org [mailto:vtkusers-bounces@vtk.org] <b>On Behalf Of </b>Bryn Lloyd<br><b>Sent:</b> Thursday, May 26, 2011 12:05 PM<br><b>To:</b> vtkusers@vtk.org<br><b>Subject:</b> [vtkusers] Mixing Boost.Python and VTK/Python<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Hi<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>A similar question has been asked here before, but I have not managed to get a working solution from it. <o:p></o:p></p><p class=MsoNormal>I have a class which returns a vtkUnstructuredGrid. I wrap my class using boost python.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'>class MyClass { <o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'>public: <o:p></o:p></span></p><p class=MsoNormal style='text-indent:.5in;text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'>vtkUnstructuredGrid* GetGrid () { return m_Grid; }<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'>private:<o:p></o:p></span></p><p class=MsoNormal style='text-indent:.5in;text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'>vtkUnstructuredGrid * m_Grid;<br>};<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'>But if I call the function GetGrid in Python:<o:p></o:p></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'>from vtk import * <o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'>from MyModule import *<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'>obj = MyClass()<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'>grid = obj.GetGrid()<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'>I get following error:<o:p></o:p></p><p class=MsoNormal style='text-autospace:none'>TypeError: No Python class registered for C++ class class vtkUnstructuredGrid<o:p></o:p></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'>The class MyClass has been wrapped as follows:<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas;color:blue'>template</span><span style='font-size:9.5pt;font-family:Consolas'><<span style='color:blue'>class</span> T><o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas;color:blue'>struct</span><span style='font-size:9.5pt;font-family:Consolas'> vtkObject_to_python<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'>{<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> <span style='color:blue'>static</span> PyObject *convert(<span style='color:blue'>const</span> T &p)<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> {<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> std::ostringstream oss;<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> oss << (<span style='color:blue'>void</span>*) &p;<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> std::string address_str = oss.str();<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> object obj = import(<span style='color:#A31515'>"vtk"</span>).attr(<span style='color:#A31515'>"vtkObjectBase"</span>)(address_str);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> <span style='color:blue'>return</span> incref(obj.ptr());<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> }<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'>};<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'>BOOST_PYTHON_MODULE(MyModule)<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'>{<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> to_python_converter<vtkUnstructuredGrid,<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> vtkObject_to_python<vtkUnstructuredGrid> >();<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> class_<MyClass>(“MyClass”)<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> .def(“GetGrid”,&MyClass::GetGrid, return_value_policy<reference_existing_object>())<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'> ;<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'>}<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal><o:p> </o:p></p></div></body></html>