[vtkusers] Filling a hole

[alex. gouaillard]

> I tried to get that to work with VTK from CVS and I must have missed
> something. Or I messed up some pipeline thing.  

It used to work with 4.2 and I admit not having paid so much attention
to maintain it since (2002). We are working on a port of CGAL surface
mesh structure to ITK (including euler operators and lot of nice
features) and on porting the equivalent of all the surface mesh
processing filters from VTK to that structure to do all the processing
in ITK. It's getting most of our time.

> Anyway I picked through
> it and that bit where the lines are made to line strips then to a poly,
> then triangulated is really nice.  
> 
> What I don't get is why the loop? Could something be left over?
> 
well, yes actually, if you have several holes.
the code picks up on border edge and go around that (hole's) border
only.

It's quite brutal though:
1: it's planar (or almost) whereas you would like it to extrapolate the
surface in some cases (C0, C1, C2, ...).
2: the points density can be very low. one would like to be able to
adjust the point density to, say, the same density as the rest of the
surface, or a curvature-dependent value.
3: shape factor of created triangles can be very very bad. It can be
addressed together with 2.

For our purpose (parameterization) we did not care about the geometry,
we just needed to fill the holes, and that was good enough.

alex