[vtkusers] How to set Rotation Point?

[Stephan Theisen]

Hi together!

I've the following question: How can I set the the Point about my Volune 
rotate?
Because my Volume rotate about a point outside of the volume and I it 
should rotate about
the center of the volume.
For help I've attached the important cutout of my programm.

        vtkVolume16Reader volumer = new vtkVolume16Reader();
        volumer.SetDataDimensions(512,512);            
        volumer.SetDataByteOrderToLittleEndian();      
        volumer.SetFilePrefix ("G:/CT-Bilder_umbenannt/quarter");
        volumer.SetImageRange(1,200);
        volumer.SetDataSpacing(0.488,0.488,1.0);                  
       
        vtkExtractVOI voi = new vtkExtractVOI();
        voi.SetInput(volumer.GetOutput());
        voi.SetVOI(110,400,30,480,0,200);
     
        vtkPiecewiseFunction opacityTransferFunction = new 
vtkPiecewiseFunction();
        opacityTransferFunction.AddPoint(1000,0.0);
        opacityTransferFunction.AddPoint(1150,1.0);
       
        vtkColorTransferFunction colorTransferFunction = new 
vtkColorTransferFunction();      
        colorTransferFunction.AddRGBPoint(255.0,1.0,0.49,0.25);
       
        vtkVolumeProperty volumeprop = new vtkVolumeProperty();
        volumeprop.SetColor(colorTransferFunction);
        volumeprop.SetScalarOpacity(opacityTransferFunction);
        volumeprop.ShadeOn();
        volumeprop.SetInterpolationTypeToLinear();
       
        vtkVolumeRayCastCompositeFunction compositefunction = new 
vtkVolumeRayCastCompositeFunction();             
        vtkVolumeRayCastMapper volumemapper = new vtkVolumeRayCastMapper();
        volumemapper.SetVolumeRayCastFunction(compositefunction);
        volumemapper.SetInput(voi.GetOutput());
       
        vtkVolume volume = new vtkVolume();
        volume.SetMapper(volumemapper);
        volume.SetProperty(volumeprop);     
       
Thank's in advance

Stephan