_imageViewer2XYZ -> SetExtentDimension(x1,x2,y1,y2,z1,z2);
_imageViewer2XYZ -> GetVtkImageViewer2()->SetupInteractor ( iren );
_imageViewer2XYZ -> SetExtentDimension(x1,x2,y1,y2,z1,z2);
_imageViewer2XYZ -> GetVtkImageViewer2()->SetupInteractor ( iren );