[vtkusers] vtkUnstructuredGrid to vtkImageData

[Jean M. Favre]

Martin Haidacher wrote:
> hello.
> 
> I want to convert a vtkUnstructuredGrid to a vtkImageData object, 
> because I want to use the data for raycasting.

You might not have to do that. See if you can use the recently released 
  vtkUnstructuredGridVolumeRayCastMapper. It is in VTK 4.4

See the example in:

Examples/VolumeRendering/Tcl/IntermixedUnstructuredGrid.tcl