Integration of a variable over a volume defined with a cad file
 

Hi everyone,
I am investigating if it is possible to integrate a scalar field stored in a rectilinear grid (vtr file, viewable in ParaView) over a volume defined with a CAD file. This cad file can be easily imported in ParaView as .stl but I wonder if I could use it to clip a region of the grid and later integrate over the resulting region. I am not sure if this could be done with some programmable filter/vtk programming or if it could be done at all. Any suggestion would be greatly appreciated!

Marco