[vtkusers] Possible bug in CVS version of vtkBandedPolyDataContourFilter?

[Amy Henderson]

Hi Charles,

Did you take a look at VTK/Graphics/Testing/Tcl/TestBandedContourFilter.tcl 
and VTK/Examples/VisualizationAlgorithms/Tcl/BandedContourTerrain.tcl? 
(There is also a python version of the one in 
Examples/VisualizationAlgorithms.)  Both of these are managing to display 
bands of cells with a different color per band.  Perhaps there is a setting 
either on this filter or in the mapper that is set differently in these 
examples than in your code.

- Amy

At 06:01 PM 9/20/2004, Charles Boivin wrote:
>Hello everyone,
>
>I have recently switched to the CVS version of VTK for a couple of
>reasons. In my application, I am using the
>vtkBandedPolyDataContourFilter module. I have noticed today that this
>stopped working the way it was before. I expect to get bands of cells
>that are all colored the same out of this filter; this certainly was
>what I was getting before with VTK 4.4.
>
>Now, the contours are generated properly but they are colored based on
>the input scalar value, not using a scalar value that is uniform within
>the contour. Hence I get a very smooth output in terms of color -- no
>specific contours can be distinguished. If I put the output in wireframe
>mode, I can verify that the contours are indeed generated, just not
>colored properly.
>
>I checked the differences between version 4.4 of the C++ file, and the
>version from CVS (updated a few minutes ago). There are some minor
>changes, but one caught my eye. At the beginning of the Execute() member
>function, there is this:
>
> >From the CVS version:
>   vtkPointData *outPD = output->GetPointData();
>
>Now, in VTK 4.4, this was:
>   vtkPointData *outPD = input->GetPointData();
>
>Certainly, the CVS version seems correct, at least based on variable
>name. I tried changing "output" to "input" back, as it was in v4.4, and
>this actually fixed my problem -- it created bands of uniformly colored
>cells.
>
>It seems like the CVS version *should* be right (in terms of that
>declaration, at least), but it does not work for me... Am I possibly
>using this module wrong? Or is there a problem in the CVS version of
>this object?
>
>Thank you for your answers,
>
>Charles Boivin
>
>
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