[Paraview] [vtkusers] Distorted Images from VTK Plugin in Paraview

[Christian Werner]

Thank you very much Jonathan, you saved my day! It indeed was because of 
uninitialized data, I just write to the output at positions that had 
foreground pixels. Very irritating though, that with VTK-only the data 
seems to always be initialized with 0.

Best regards,
Christian


Jonathan Winterflood wrote:
> Hi,
>
> I don't really understand your code (complete Vtk beginner here), but 
> the artefacts in your paraview output look very much like 
> uninitialized data. ie: it looks you paint the objects, but do not 
> clear the background first.
>
> Doesn't entirely explain why plain vtk does not have this problem, but 
> I expect that paraview is more complex, maybe increasing the chances 
> that you end up getting some recycled memory?
>
> HTH
> (Posted off-list since I'm really not sure...)
> --
> Jonathan
>
>
> On Mon, Mar 22, 2010 at 04:46, Christian Werner 
> <christian.werner at rwth-aachen.de 
> <mailto:christian.werner at rwth-aachen.de>> wrote:
>
>     I don't know how close the developers of VTK and ParaView work
>     together, but maybe some VTK expert is more likely to know a
>     solution to this...? This is my posting in the ParaView Mailing list:
>
>     Hello!
>
>     I am again having bad results in ParaView with my custom VTK
>     filters (you might notice that this is not the first time). I just
>     don't know what the problem is. Again, the filter works perfectly
>     in VTK-only, but in ParaView my result image has some serious
>     errors (always, no switching behaviour this time...).
>     I have attached three images. The first one shows the original,
>     the second shows the result in vtk-only (removal of small
>     objects), the third shows the exact same filter compiled as a
>     ParaView plugin.
>
>     I have already spent a lot of time looking at examples and reading
>     matching chapters in the VTK Users Guide, I just do not see what I
>     am doing wrong. In my code, I use recursion to traverse through
>     connected components and pass on scalar pointers, is that a
>     problem?? At least some more basic filter doesn't produce errors.
>     Or maybe I mistype something? Am I breaking important rules? Is my
>     coding style intrinsically error prone?
>
>     I'd really appreciate if somebody could look into this. I also
>     attached the very well documented code.
>
>
>     Best regards,
>     Christian
>
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