how can I show molecular orbital with vtk

I want read a gaussian cube file with vtkGaussianCubeReader and show isosurface of the Molecular orbitals similar as image
I found some class such as vtkProgrammableElectronicData and vtkMolecule but I dont know how can I send cube file data to them.
can anyone help me how to do this?

Thank you.

@nicolas.vuaille