[vtkusers] Subdomains in vtk

[Andrew E Slaughter]

I am working on a VTK unstructured mesh and would like to include a 
subdomain ID for each cell that indicates different parts of the mesh. I 
then need to export this using the vtkExodusIIWriter. I noticed that 
vtkExodusIIWriter has a WriteOutBlockIdArrayOn () member. If I use this, 
what part of the VTK unstructured mesh is taken to be an ExodusII block 
ID? That is, where in the VTK unstrcutured mesh do I store this ID so 
that my ExodusII file will contain the ID when exported?

Thanks,
Andrew