[vtkusers] Multiple domains in VTU files

[Martin Vymazal]

Dear vtk users & developers,

 is it possible to store multiple domains in vtu "unstructured grid" files? I 
know I can write multiple 'pieces' with their own points, cells, point data 
and cell data. The problem is that when I open such a file with paraview, I 
have no way of distinguishing the sub-domains. I would like to store a mesh 
and some cfd data in such a way that I can select for example only the 
boundary of my domain. Is this supported?

Thank you,

  Martin Vymazal