On Wed, Dec 21, 2011 at 3:38 AM, andon <antoniod987 at gmail.com> wrote: > In your opinion could be usefull this example: > http://www.vtk.org/Wiki/VTK/Examples/Cxx/PolyData/SelectPolyData? How do you want them to specify the ROI? Maybe you're looking for something like this:? http://www.vtk.org/Wiki/VTK/Examples/Cxx/Picking/AreaPicking David