[vtkusers] 3D mesh simplification/decimation

[Jasper VTK]

Dear VTK User community,

I have been using VTK for quite some time now, for basic visualization. 
I would like to pose the following question to the more advanced users 
of VTK.

The used dataset is a very large mesh, obtained from a Nastran FE Model. 
It is a vtkUnstructuredGrid with VTK_TETRA cells.

I have successfully performed a mesh decimation, by first extracting the 
polydata (surface polygons) from the unstructuredGrid and using the 
decimatePro filter. This gives very good results, but we also need a 
full 3D mesh simplification.

What we want to do is to reduce the mesh density of the entire model. 
This reduced mesh would then be used to do some interpolation, appending 
data etc, and after that the plan is to sample the data of this 
simplified (rough) mesh onto the large detailed mesh. Thus, saving a lot 
of computation time on the interpolation end other operations performed.

So my question is, is it possible to do a full 3D mesh simplification 
using the tools currently provided by VTK? Or does anybody has an idea 
of an alternative method to achieve this goal?

Thanks in advance!

Kind regards,
Jasper C