[vtkusers] Get the pointer of Scalar data

[Matthias Guenther]

Hi,

I'm not a VTK expert, but you could try to update your pipeline before
accessing the pointer.
See below.

Jianlong Zhou wrote:
> 
> hi, all,
> 
> I write a vtk pipeline to computer gradient magnitude of volume data.
> I want to get the pointer to this gradient magnitude. I wrote the
> following pipeline.But I cannot get the pointer to this gradient
> magnitude. The value of the pointer is always 0x0000000.Is there any
> other method to get scalar pointer? How to get the pointer to the
> gradient magnitude?
> 
> My pipeline is like this:
> 
> vtkImageGradientMagnitude *gradient=vtkImageGradientMagnitude::New();
>      gradient->SetDimensionality( 3);
>      gradient->SetInput(reader->GetOutput());
> 

Add something like that here:
gradient->Update();

> ////Following line is to get scalar pointer, but I can not get its
> pointer.
> unsigned short *Pointer = (unsigned short
> *)gradient->GetOutput()->GetScalarPointer();
>    ..............
> 
> Thank you in advance.
> 
> Jianlong

I hope, that helps.

Bye,
  Matthias