[vtkusers] I need to get the X, Y, Z coordinates of a point in a vtkPolyData

[Bill Lorensen]

contour.GetOutput().GetPoints( ).GetPoint( pointId, coord )

On Mon, Oct 26, 2009 at 9:50 AM, Alessandro Artusi
<artusialessandro4 at googlemail.com> wrote:
> Thanks Jerome,
>
> it is very helpfull your explanation. In my case what i can use to get the
> info that i need.
> From the Online documentation is not clear to me how the get access to the
> x,y,z coordinates making use of the function available to vtkContourFilter.
> Any suggestion?
> Thanks again.
> Alessandro.
> On Mon, Oct 26, 2009 at 3:31 PM, Jérôme <jerome.velut at gmail.com> wrote:
>>
>> In your code, you defined contour as the vtkContourFilter, not a polydata.
>> vtkContourFilter is a subclass of vtkAlgorithm that does not have a
>> GetPoints( ) function. You should take a look to VTK online documentation to
>> see what you can access from a class.
>> Basically, a subclass of vtkAlgorithm allows you to access input/ouput
>> that could be vtkPointSet
>> From vtkPointSet (such as vtkPolyData, your interest...), you can acces
>> geometry through GetPoints( ) or topology through GetLines( ), GetVerts(),
>> GetPolys( ),...
>>
>> In your case (from what I read  in your code), contour is a vtkAlgorithm.
>> It cannot be its own output in the same time.
>>
>> I hope that helps
>>
>> Jerome
>>
>> 2009/10/26 Alessandro Artusi <artusialessandro4 at googlemail.com>
>>>
>>> Dear Bill thanks a lot but it does not work I have still the same
>>> Attribute error.
>>>
>>> I repeat contour is where i store the output of teh vtkContourFilter(),
>>> may be it does not inerithance the GetPoints().....
>>>
>>> Any other suggestion?
>>>
>>> The vtkContourFilter has not any
>>>
>>> On Mon, Oct 26, 2009 at 2:44 PM, Bill Lorensen <bill.lorensen at gmail.com>
>>> wrote:
>>>>
>>>> You must do
>>>> contour.Update()
>>>>
>>>> before accessing the points.
>>>>
>>>> On Mon, Oct 26, 2009 at 8:26 AM, Alessandro Artusi
>>>> <artusialessandro4 at googlemail.com> wrote:
>>>> > Thanks a lot Jerome,
>>>> >
>>>> > I get an errore:
>>>> >
>>>> > AttributeError GetPoints.
>>>> >
>>>> > May be I am doing something wrong; what i  am doing is the following:
>>>> >
>>>> > contour = vtk.vtkContourFilter()
>>>> > contour.SetInput(grid) #grid is rectilineargrid()
>>>> > contour.ComputeNormalOn()
>>>> > contour.SetValue(0, 95) #my isovalue
>>>> >
>>>> > in contour i should have my polyData right?
>>>> >
>>>> > when i do what you suggested:
>>>> >
>>>> > contour.GetPoints( ).GetPoint( pointId, coord )
>>>> >
>>>> > I got the error.
>>>> >
>>>> > Any suggestion?
>>>> >
>>>> > Thanks again,
>>>> > Alessandro.
>>>> >
>>>> >
>>>> > On Mon, Oct 26, 2009 at 1:11 PM, Jérôme <jerome.velut at gmail.com>
>>>> > wrote:
>>>> >>
>>>> >> Hi,
>>>> >> vtkPolyData is a vtkPointSet : you can access points coordinates
>>>> >> through
>>>> >>
>>>> >> polydata->GetPoints( )->GetPoint( pointId, coord )
>>>> >>
>>>> >> where polydata is your... polydata, pointId is the point Id you want
>>>> >> to
>>>> >> get (from 0 to NumberOfPoints - 1) and coord is double coord[3]
>>>> >> filled by
>>>> >> the point coordinate.
>>>> >>
>>>> >> HTH
>>>> >> Jerome
>>>> >>
>>>> >> 2009/10/26 Alessandro Artusi <artusialessandro4 at googlemail.com>
>>>> >>>
>>>> >>> Dear All,
>>>> >>>
>>>> >>> I have a vtkPolyData from the vtkContourFilter and I need to get the
>>>> >>> X,Y,Z coordinates of each point in the PolyData. This because I need
>>>> >>> to
>>>> >>> convert them.
>>>> >>> How can i get this info?
>>>> >>>
>>>> >>> Thanks a lot for teh help,
>>>> >>> Alessandro.
>>>> >>>
>>>> >>>
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>>>> >
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