CGAL users discussion list

["Sebastien Loriot (GeometryFactory)" <>]

You can try using the edge simplification algorithm [1]
There is an example given in this thread (second post) [2]

Let us know if this does not solve the problem.

Sebastien.

[1] 
http://www.cgal.org/Manual/latest/doc_html/cgal_manual/Surface_mesh_simplification/Chapter_main.html
[2] 
http://cgal-discuss.949826.n4.nabble.com/understanding-edge-collapse-tt3248855.html

On 10/24/2012 01:51 AM, Richard Downe wrote:
> I have a program that uses Nef_Polyhedron_3 to merge several disjoint
> structured grids, and then remeshes the surface using a delaunay
> triangulation. Out of several surfaces I'm preparing, one has stubbornly
> refused to mesh. After a day or so of tweaking the parameters, I
> generated .off files to permit me to visualize the intermediate surface
> and troubleshoot.
>
> In examining the .off version of the troublesome surface, I noticed that
> there are several degenerate triangles (e.g., 2 coincident vertices, and
> therefore a zero-valued normal). I'm assuming this has to do with
> distances in the EPECK kernel that are too small to represent in the
> EPICK kernel, which therefore get rounded off.
>
> My question is this: does a filter exist which can remove these
> triangles *prior* to casting the polyhedron to an EPICK kernel? Or am I
> on my own (e.g., either filtering the inexact kernel version and simply
> erasing the degenerate triangles, or alternately, filtering the exact
> one and merging any triangle with a sufficiently high aspect ratio with
> an adjacent triangle in the hopes of avoiding degeneracy post-cast)?
>
> Any help would be very much appreciated.
>
> -Richard