[vtkusers] How to extract Scalar and Point Data from ProbeFilter?

[Eric E. Monson]

Hello,

Make sure you call probe.Update() before you try to read the output. Normally the pipeline is only updated when the system needs the information for a sink like displaying or saving, but if you're trying to access it before that point you need to call Update manually first. Also, since the data already exists (or will after you update), you don't need to set "data" data type or allocate memory. (You should do the former if you're making a copy of the data rather than accessing it "in place".) So, I think you can change your example to:

// ----------------------------
probe = vtk.vtkProbeFilter()  # or  cutter = vtk.ctkCutter()
...
probe.Update()
data = probe.GetOutput().GetPointData().GetScalars()
print data
// ----------------------------

-Eric

------------------------------------------------------
Eric E Monson
Duke Visualization Technology Group


On Jan 26, 2011, at 3:23 AM, FUJII Kenji wrote:

> Hi there,
> 
> I want to extract Point and Scalar Data from ProbeFilter that was Probing or Cutting from Polydata.
> 
> To extract them, I was trying to call some function (GetOutput, GetPointData, GetScalars etc...)
> But It doesn't work well. What I tried in Python is as follows.
> 
> // ----------------------------
> probe = vtk.vtkProbeFilter()  # or  cutter = vtk.ctkCutter()
> ...
> data = vtk.vtkDoubleArray()
> data.SetNumberOfComponents(1)
> data.SetNumberOfTuples(20*20)
> data = probe.GetOutput().GetPointData().GetScalars()
> print data
> // ----------------------------
> 
> The result of  "print data" was (None).
> I think vtkProbeFilter and vtkCutter may not have Point and Scalar data.
> 
> Please reply if someone knows how to extract their data.
> 
> Regards,
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
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