[vtkusers] Sharing a vertex list among separate vtkPolyData objects

[Michael Jackson]

I am currently working with a surface Mesh that has about 25 Million  
vertices in it. Within the surface mesh there are separate  
"grains" (Metallurgical Microstructure). We would like to visualize  
each grain separately. This can be achieved using the Threshold filter  
(for starters) or probably some custom filter. My current question is  
that if I end up creating say 4800 individual vtkPolyData objects and  
I set the master list of vertices into each of those 4800 vtkPolyData  
objects, will vtk, for any reason end up making copies of that master  
list?
   My understanding from walking through some of the vtk code is that  
it looks like the vtkPolyData object will just get a reference to the  
vtkPoints object (thus increasing its ref count) and use that. I was  
wondering if there were any circumstances where the master list would  
be copied? Further down a pipeline for instance? Maybe in ParaView's  
pipeline?

  Thanks for any insights.
___________________________________________________________
Mike Jackson                      www.bluequartz.net
Principal Software Engineer       mike.jackson at bluequartz.net
BlueQuartz Software               Dayton, Ohio