[vtkusers] problem with vtkDijkstraGraphGeodesicPath() and vtkXMLPolyDataReader output

[David Doria]

On Sat, Dec 26, 2009 at 8:07 PM, superzz <jxdw_zlf at yahoo.com.cn> wrote:
>
> Hello Karthik
> Can you tell me how to run TestDijkstraGraphGeodesicPath?
> I run it with the command "WidgetsCxxTests.exe TestDijkstraGraphGeodesicPath
> 13". But it tells me dbgdel.cpp#line 52,
> "_BLOCK_TYPE_IS_VALID)(pHead->nBlockUse)".
>
> Thanks
>
> superZZ
>
>
> Karthik Krishnan-2 wrote:
>>
>> You need to post the polydata that you have. You've mentioned yourself
>> that it does work with the sphere source. So there must be an issue
>> with your data that results in no path being found between the source
>> and end vertex. Perhaps  you can try to run a connectivity filter on
>> the dataset to see if one can indeed traverse on the edges between the
>> two vertices.
>>
>> This class is tested on terrain polydata and used to draw
>> interactively on polygonal datsets. See
>> TestDijkstraGraphGeodesicPath.cxx . There are no known issues with it.
>>
>>
>> --
>> karthik
>>
>> On Tue, Oct 20, 2009 at 5:45 AM, RimAY <rim.ayari at gmail.com> wrote:
>>>
>>> Dear All ,
>>>
>>> I try to get the shortest path  between two cell in a vtk image, then
>>> trace
>>> it with vtkTubeFilter(). I read the vtk file and get the output of the
>>> vtkXMLPolyDataReader(). then I choose two cell: start_point and end_point
>>> to
>>> find the shortest path  between them. My problem is that I got always the
>>> error:
>>>
>>> vtkTubeFilter (0F432C08): Less than two points in line! or
>>>
>>> I use the same code with the vtkSphereSource output and it work.
>>> this is a part of my code:
>>>
>>> readerVTK = vtkXMLPolyDataReader()
>>> readerVTK.SetFileName("file")
>>> readerVTK.Update()
>>>
>>> data = vtkPolyData()
>>> data = readerVTK.GetOutput()
>>> data.Update()
>>>
>>> geodesic = vtk.vtkDijkstraGraphGeodesicPath()
>>> geodesic.SetInput(data)
>>> geodesic.SetStartVertex( start_point )
>>> geodesic.SetEndVertex( end_point )
>>> geodesic.Update()
>>>
>>> points = vtkPolyData()
>>> points = geodesic.GetOutput()
>>>
>>> tube = vtk.vtkTubeFilter()
>>> tube.SetInput(points)
>>> tube.SetRadius(1.5)
>>> tube.Update()
>>>
>>> tubeMapper = vtkPolyDataMapper()
>>> tubeMapper.SetInputConnection(tube.GetOutputPort())
>>>
>>>
>>> Any help will be very appreciated
>>> Best Regards
>>>
>>>
>>>
>>>
>>>
>>> --
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>>> Sent from the VTK - Users mailing list archive at Nabble.com.
>>>
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>
> --
> View this message in context: http://old.nabble.com/problem-with-vtkDijkstraGraphGeodesicPath%28%29-and-vtkXMLPolyDataReader-output-tp25972428p26931483.html
> Sent from the VTK - Users mailing list archive at Nabble.com.

Looks like an example is in order :)

superZZ, if you can get the test to work, maybe you can add a small
example here:
http://www.cmake.org/Wiki/index.php?title=VTK/Examples/Graph/ShortestPath&action=edit&redlink=1

Thanks,

David