Hi Hamid,<div>Try vtkExtractGeometry: <a href="http://www.vtk.org/doc/release/5.4/html/a00505.html">http://www.vtk.org/doc/release/5.4/html/a00505.html</a></div><div><br></div><div>It can &quot;extract cells that lie either entirely inside or outside of a specified implicit function&quot;</div>

<div><br></div><div>Seth</div>