[vtkusers] creating a 3D body using unstructured grid

[Paul McGuinness]

Hi vtk users,

I am wondering if anyone can help me? Here is my problem:
I would like to create a 3D cell from data that describes the shape of my
body. The surface of the body is created very simpler to that of the cube
in Cube.cxx.
Instead of using vtkPolydata I am using vtkUnstructuredGrid. My surface is
made up of 2D triangles (triangular facets), so at the moment the number
of
cells in my unstructured grid is equal to the number of triangles that
describe my surface. But I would like to apply a density value to the
entire body (body->GetCellData()->SetScalars(density_scalars)), but at the
moment the cells describe the shape of my body and not the body itself.
Is there any way to create a 3D body from an enclosed surface created by
2D triangles?

Thanks,
Paul.