Thank you the suggestions.
If I understand your steps correctly, I need to create points, pass the points to Delaunay and execute a function within Delaunay that returns the mesh.
I have had a look at the vtkDelaunay3D cxx example which reads in points from a file and uses the SetInputConnection function to pass outputs of a filter as input to another filter. What remains unclear to me is how to pass a vtkPointSet (or vtkPoint, used by me) to vtkDelaunay3D. Could you kindly help with this? My c++ skills are still under development. Thanks.