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</o:shapelayout></xml><![endif]--></head><body lang=EN-GB link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='color:#1F497D'>Hello,<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'>So as explained previously, I want to assign information to edges in a vtkPolyData and pass it through filters.<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 just wanted to add more information about what was tried or considered.<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'>Thoughts: <o:p></o:p></span></p><p class=MsoListParagraph style='text-indent:-18.0pt;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='font-family:Symbol;color:#1F497D'><span style='mso-list:Ignore'>·<span style='font:7.0pt "Times New Roman"'> </span></span></span><![endif]><span style='color:#1F497D'>Most methods that involve referring to a filter’s input point IDs won’t work since the point IDs will be different in the output.<o:p></o:p></span></p><p class=MsoListParagraph style='text-indent:-18.0pt;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='font-family:Symbol;color:#1F497D'><span style='mso-list:Ignore'>·<span style='font:7.0pt "Times New Roman"'> </span></span></span><![endif]><span style='color:#1F497D'>Using Pedigree IDs. This seemed promising at first but it turns out the Pedigree IDs are “per point” or “per polygon”, and can’t be defined “per edge”. Using the “per point” method where points involved in flagged edges are set to “ON” would not work because it doesn’t handle ambiguous cases of three points belonging to the same triangle that has two flagged edges. There is a way to encode the edge information in each triangle (edge 1 of this triangle is flagged, etc.), but this added logic is not handled seamlessly by the classes that deal with passing the pedigree IDs to the new vtkPolyData.<o:p></o:p></span></p><p class=MsoListParagraph style='text-indent:-18.0pt;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='font-family:Symbol;color:#1F497D'><span style='mso-list:Ignore'>·<span style='font:7.0pt "Times New Roman"'> </span></span></span><![endif]><span style='color:#1F497D'>If a filter modifies the topology of the vtkPolyData, I would like the 2 edges generated from splitting a “flagged edge” to also inherit from the “flagged” information.<o:p></o:p></span></p><p class=MsoListParagraph style='text-indent:-18.0pt;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='font-family:Symbol;color:#1F497D'><span style='mso-list:Ignore'>·<span style='font:7.0pt "Times New Roman"'> </span></span></span><![endif]><span style='color:#1F497D'>Methods that compare point coordinates before and after to recover the information would not work for filters that modify the position of points.<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'>It seems like a useful “standard” thing to expect VTK to be able to do, especially as it seems like the necessary code is in place to allow this for cells and points…<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'>Does anyone have any ideas?<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'>Thanks,<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'>Viet<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 0cm 0cm 0cm'><p class=MsoNormal><b><span lang=EN-US style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span lang=EN-US style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> Viet Bui Xuan [mailto:v.buixuan@simpleware.com] <br><b>Sent:</b> 06 May 2014 16:11<br><b>To:</b> 'vtkusers@vtk.org'<br><b>Subject:</b> Edge flagging in vtkPolyData<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Hello everyone,<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I have come across a problem that doesn’t seem to have an obvious solution, when looking at the VTK documentation.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Perhaps more experienced VTK users can put me on the right track!<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Goal:<o:p></o:p></p><p class=MsoNormal>I’ve got a vtkPolyData and we allow users of the application to flag/select some edges. I would like to be able to encode the edge information in a way that would allow me to apply any user selected filter without having to worry about keeping track explicitly (i.e. modify each filter) of the edges that were flagged.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I hope this question makes sense. Please don’t hesitate to ask me if something’s not clear. And of course any input/advice would be very welcome!<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Cheers,<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><span lang=FR>Viet<o:p></o:p></span></p></div></body></html>