[Gmsh] 2D meshing pecularities

[Christophe Geuzaine]

"Pascal A. Dupuis" wrote:
> 
> Hello,
> 
> I am trying to nail down a 2D meshing problem; here is a minimal test case.
> I have a geometry mostly done of half cyliders. To verify the design coherency,
> I regulary generate a 2D meshing: in this case, most are 'ruled surface'
> delimited by two lines and two half circles. As it appears, the intermediate
> points generated on the ruled surface are incorrect and seems to fall outside
> the surface. The following commands illustrate this behaviour:

Yes, this is normal (!). You cannot define surfaces for which the plane
projection is degenerate (cf. FAQ 5.2). In your case, you should not use
half circles, but only arcs having an angle smaller than 2*Pi.

There have been several messages on the mailing list about this
phenomenon. I will add a explicit warning in the FAQ ;-)

Christophe

-- 
Christophe Geuzaine

Tel: (626) 395-4552    http://www.geuz.org
Fax: (626) 578-0124    mailto:geuzaine at acm.caltech.edu