[vtkusers] reduce the number of triangles

[Pethes Róbert]

Dear list members,

I am looking for a procedure to reduce the number of triangles in a 
triangle mesh.

Firstly, I tried the vtkDecimatPro class, and I have some question about this:
- Is it possible to fix edges, witch edges would be constant after the 
decimation process?
- Is it possible to know the origin of an edge in the new mesh (for 
example, if delete boundary is off, what are the origin of the boundary 
edges in the new mesh)?

Does somebody have any experience about vtkDecimate, vtkDecimatePro and 
vtkQuadricDecimation classes? Which is the best solution?

Róbert Pethes