[vtk-developers] Geodesics on polygonal surfaces

[Karthik Krishnan]

Hi,

I'm writing a widget that can draw on polygonal datasets. So an need an
algorithm that can trace geodesics on surfaces. I dug up an old thread :
  http://public.kitware.com/pipermail/vtkusers/2005-June/080306.html

I played around with Rasmus Paulsen's code that computes the Dijkstra's
shortest path between two vertices (Graph geodesics). [
http://www2.imm.dtu.dk/~rrp/VTK/], hoping to get the shortest path using
Dijkistra and then try to smooth the resulting zig-zagged curve.

It sort of works if the mesh is very dense. Often, it gives non-intuitive
results.

Attached is an example:

- The input polydata is
http://public.kitware.com/pub/itk/UsersITK/vtkDijkstra/ellipsoid.png
- The result is :
http://public.kitware.com/pub/itk/UsersITK/vtkDijkstra/DijkstraGeodesic1.png

The curve ends up hugging the latitudes of the ellipsoid for a while to get
to its final destination, instead of zigzagging its way through the
latitudes and longitudes.

Any thoughts. Anybody else using geodesics for similar purposes ?

Thanks

-- 
Karthik Krishnan
R&D Engineer,
Kitware Inc.
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