[vtkusers] modification to vtkDelaunay2D for topographical models?

[Jean-Dominique Barnichon]

hi all,

I am building a 3D mesh of a topographical model.
The input data consist mainly of constrained lines (level curves), and only
of few points.
I use the vtkDelaunay2D filter to perform constrained triangulation, which
works fine.

However, the level curves being generally not convex, I end up with some
mesh triangles (located at concavity of level curves) that have their 3
points lying on the same level curve.
As a result, such triangles define flat faces (in the topographical sense),
which is a bit of a non-sense as faces between level curves are generally
not flat.

The solution could be either :
- to modify vtkDelaunay2D filter such that this type of triangle (3 pts
belonging to the same constrained line) does not exist,
- or to create a filter that would take as input the vtkDelaunay2D output
and the input lines, and that would modify the mesh such that this type of
triangles would be removed or redistributed.

Before going into one of these solutions (is there a better one?), I was
wondering if somebody has already faced this problem, and found an answer.
Any idea/advice are welcomed.

Jean-Do