[Gmsh] Lloyd smoothing broken?

[Nico Schlömer]

Thanks Christophe for speedy explanation.

Cheers,
Nico

On Wed, Mar 8, 2017 at 8:17 PM Christophe Geuzaine <cgeuzaine at ulg.ac.be>
wrote:

>
> Hi Nico,
>
> It's not a bug, it's a feature (for quad mesh generation). See
> http://link.springer.com/chapter/10.1007%2F978-3-642-24734-7_26 for some
> context.
>
> Christophe
>
> > On 8 Mar 2017, at 09:46, Nico Schlömer <nico.schloemer at gmail.com> wrote:
> >
> > Hi everyone,
> >
> > When using `-optimize_lloyd`, I noticed that gmsh doesn't produce
> centroidal tesselations but for some reason favors right angles. For the
> simple circle geometry
> > ```
> > // Points
> > p1 = newp;
> > Point(p1) = {0, 0, 0, 0.1};
> > p2 = newp;
> > Point(p2) = {1, 0, 0, 0.1};
> > p3 = newp;
> > Point(p3) = {0, 1, 0, 0.1};
> > p4 = newp;
> > Point(p4) = {-1, 0, 0, 0.1};
> > p5 = newp;
> > Point(p5) = {0, -1, 0, 0.1};
> > // Circle arcs
> > c1 = newl;
> > Circle(c1) = {p2, p1, p3};
> > c2 = newl;
> > Circle(c2) = {p3, p1, p4};
> > c3 = newl;
> > Circle(c3) = {p4, p1, p5};
> > c4 = newl;
> > Circle(c4) = {p5, p1, p2};
> > l1 = newl;
> > Compound Line(l1) = {c1,c2,c3,c4};
> > ll1 = newll;
> > Line Loop(ll1) = {l1};
> > surf1 = news;
> > Plane Surface(surf1) = {ll1};
> > ```
> > meshed with
> > ```
> > gmsh -2 circle.geo -o circle.msh -optimize_lloyd 1000
> > ```
> > I'm getting [1] when it should really look like [2].
> >
> > Any hints on what might be going wrong?
> >
> > Cheers,
> > Nico
> >
> > [1] http://chunk.io/f/edd6327ec586485b9c8fe7a96ba1df9a
> > [2] http://chunk.io/f/5ba441e4700a4fad8be754c4f19dd9c6
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>
> --
> Prof. Christophe Geuzaine
> University of Liege, Electrical Engineering and Computer Science
> http://www.montefiore.ulg.ac.be/~geuzaine
>
> Free software: http://gmsh.info | http://getdp.info | http://onelab.info
>
>
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