[Paraview] TransformFilter problems

[Berk Geveci]

Ah, that was easy! If you look at the signature of GetOutput(), you'll
find out that it returns vtkPointSet (see vtkPointSetAlgorithm.h).
That method gets the output and SafeDownCasts it to vtkPointSet, hence
the NULL. Try using GetOutputDataObject(0) instead.

-berk

On Wed, Jun 11, 2008 at 5:10 AM, Paul Edwards <paul.m.edwards at gmail.com> wrote:
> I've created a simple program to demonstrate the problem.  I tried to
> debug but I'm not sure what to look for....
>
> I'm still getting this error:
>
> Warning: In /home/paul/workspace/ParaView3/VTK/Filtering/vtkDataObject.cxx,
> line 908
> vtkMultiBlockDataSet (0x622ec0): Attempted to ShallowCopy from null.
>
> I've forwarded this to the VTK list in case anyone can help there.
>
> BTW I'm using the latest CVS version of VTK from the ParaVIew source tree.
>
> Any help here would be appreciated,
> Paul
>
>
> 2008/6/10 Berk Geveci <berk.geveci at kitware.com>:
>> I am guessing it is failing in
>> vtkPointSetAlgorithm::RequestDataObject(). Try putting a breakpoint
>> there.
>>
>> -berk
>>
>> On Tue, Jun 10, 2008 at 10:37 AM, Paul Edwards <paul.m.edwards at gmail.com> wrote:
>>> The seg fault is because I just used the C++ delete rather than the
>>> VTK version, i.e. this->Transform->Delete() in the destructor.  So, I
>>> still have this error:
>>>
>>>>> Warning: In /home/paul/workspace/ParaView3/VTK/Filtering/vtkDataObject.cxx,
>>>>> line 908
>>>>> vtkMultiBlockDataSet (0x173da00): Attempted to ShallowCopy from null.
>>>
>>> Regards,
>>> Paul
>>>
>>> 2008/6/10 Berk Geveci <berk.geveci at kitware.com>:
>>>> Can you post the source code for the transform filter? It is somehow
>>>> failing (returning 0) during RequestDataObject() (which may be in the
>>>> superclass). Do you have that method implemented by any chance?
>>>>
>>>> -berk
>>>>
>>>> On Tue, Jun 10, 2008 at 8:06 AM, Paul Edwards <paul.m.edwards at gmail.com> wrote:
>>>>> I am trying to use a subclass of TransformFilter in one other Filters
>>>>> (subclass of vtkMultiBlockDataSetAlgorithm) in the RequestData method.
>>>>>  The RequestData looks like this:
>>>>>
>>>>> 8<----------------------------------------------------------
>>>>> int vtkFilter::RequestData(vtkInformation* info,
>>>>>                vtkInformationVector** vector,
>>>>>                vtkInformationVector* outputVector)
>>>>> {
>>>>>        vtkInformation* outInfo = outputVector->GetInformationObject(0);
>>>>>        vtkMultiBlockDataSet* output = vtkMultiBlockDataSet::SafeDownCast(
>>>>>            outInfo0->Get(vtkMultiBlockDataSet::DATA_OBJECT()));
>>>>>
>>>>>        vtkSmartPointer<vtkMyMultiBlockDataSetReader> reader =
>>>>> vtkSmartPointer<vtkMyMultiBlockDataSetReader>::New();
>>>>>        // setup reader here...
>>>>>        // .....
>>>>>        vtkSmartPointer<vtkXYZTransformFilter> transform =
>>>>> vtkSmartPointer<vtkXYZTransformFilter>::New();
>>>>>        transform->SetInput(reader->GetOutput());
>>>>>        transform->Update();
>>>>>        output->ShallowCopy(transform->GetOutput());
>>>>>        return 1;
>>>>> }
>>>>> ---------------------------------------------------------->8
>>>>>
>>>>> This filter above will work without the transform and the transform
>>>>> works as a filter in paraview but when I have it as above I get the
>>>>> following error:
>>>>>
>>>>> 8<----------------------------------------------------------
>>>>> ERROR: In /home/paul/workspace/ParaView3/VTK/Filtering/vtkExecutive.cxx,
>>>>> line 757
>>>>> vtkStreamingDemandDrivenPipeline (0x4a7b1b0): Algorithm
>>>>> vtkXYZTransformFilter(0x4a0c7a0) returned failure for request:
>>>>> vtkInformation (0x4a7a9a0)
>>>>>  Debug: Off
>>>>>  Modified Time: 202678
>>>>>  Reference Count: 1
>>>>>  Registered Events: (none)
>>>>>  Request: REQUEST_DATA_OBJECT
>>>>>  FORWARD_DIRECTION: 0
>>>>>  FROM_OUTPUT_PORT: 0
>>>>>  ALGORITHM_AFTER_FORWARD: 1
>>>>>
>>>>> ERROR: In /home/paul/workspace/ParaView3/VTK/Filtering/vtkExecutive.cxx,
>>>>> line 757
>>>>> vtkStreamingDemandDrivenPipeline (0x4a7b1b0): Algorithm
>>>>> vtkXYZTransformFilter(0x4a0c7a0) returned failure for request:
>>>>> vtkInformation (0x4a7a9a0)
>>>>>  Debug: Off
>>>>>  Modified Time: 202710
>>>>>  Reference Count: 1
>>>>>  Registered Events: (none)
>>>>>  Request: REQUEST_DATA_OBJECT
>>>>>  FORWARD_DIRECTION: 0
>>>>>  FROM_OUTPUT_PORT: 0
>>>>>  ALGORITHM_AFTER_FORWARD: 1
>>>>>
>>>>> Warning: In /home/paul/workspace/ParaView3/VTK/Filtering/vtkDataObject.cxx,
>>>>> line 908
>>>>> vtkMultiBlockDataSet (0x173da00): Attempted to ShallowCopy from null.
>>>>> ---------------------------------------------------------->8
>>>>>
>>>>> Can anyone see what I am doing wrong?
>>>>>
>>>>> Thanks in advance,
>>>>> Paul
>>>>> _______________________________________________
>>>>> ParaView mailing list
>>>>> ParaView at paraview.org
>>>>> http://www.paraview.org/mailman/listinfo/paraview
>>>>>
>>>>
>>>
>>
>