[vtk-developers] SafeDownCast returns NULL for derived data type

[Pelt, R.F.P. van]

Dear all,

Recently, I'm working on a reader derived from vtkMedicalImageReader2.
I've also declared my own data type:

#include "vtkImageData.h"

class qfeVTIImageData : public vtkImageData
{
public:
  static qfeVTIImageData *New();

  vtkTypeMacro(qfeVTIImageData,vtkImageData);

  vtkSetMacro(PhaseCount, int);
  vtkGetMacro(PhaseCount, int);

  ...

When I attempt a SafeDownCast to vtkImageData, the macro returns NULL.
It seems like the IsTypeOf does not traverse up the hierarchy to vtkObjectBase.
Anyone know what could be the issue here?

When using a static_cast, I can get the data object.
However, the added variables in the derived data type  (e.g., phasecount in the example above),
give an error upon assignment. I guess this memory is not allocated.
What am I doing wrong here?

Thanks.

Roy


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