[vtkusers] How to clip volume?

[yichicheng]

Hi all, 
   I would like to clip a volume with select reigon, how can I achieve this? I can clip the surface on marching cube object. and I hope I can use 'vtkClipVolume' to clip a selected volume which is defined with 'vtkImplictVolume'. 
  
   My source is CT images, I render it with marching cube method, any one could give me an example how to clip a volume in vtk? Thanks in advance!

Sincerely,

Aaron