[Gmsh] Node ordering for quadratic elements
Christophe Geuzaine
cgeuzaine at ulg.ac.be
Sun Feb 24 18:56:14 CET 2008
Kris Van den Abeele wrote:
> Hi,
>
> My name is Kris Van den Abeele, I am a PhD student at VUB (research
> group of Prof Lacor). I am working on the development high-order
> Spectral Volume and Spectral Difference methods, which I implement in
> the VKI COOLFluiD code. I've been using Gmsh (Version 2.0.8, on Linux)
> as a mesh generator for a long time now and I am very happy with it.
>
> Lately, I've been creating meshes consisting of quadratic (27 nodes)
> hexahedral elements, and I've encountered a problem. On the website, I
> have not found the order in which the nodes of such a quadratic
> hexahedron are written to the mesh file. I have two different meshes,
> and it seems that for two different meshes, the order in which the nodes
> are outputted differs (more specifically for the nodes that lie in the
> center of a face).
Hi Kris - The second order nodes are given in the following order:
first, the nodes associated with edges are given in the order of the
edges; then, the nodes associated with faces are given in the order of
the faces. The ordering of the edges and the faces is given here:
http://geuz.org/gmsh/doc/texinfo/gmsh_10.html#SEC71
Can you check if your meshes are consistent with the docs? If not, it's
a bug and we will fix it.
Take care,
Christophe
>
> In attachment, I have included the .geo and .msh (Version 1.0) files
> corresponding to the two meshes.
>
> Could you have a look at this, or maybe send me the order in which the
> nodes are outputted?
>
> Thanks in advance!
> Best regards,
> Kris Van den Abeele
>
>
>
>
> ------------------------------------------------------------------------
>
> _______________________________________________
> gmsh mailing list
> gmsh at geuz.org
> http://www.geuz.org/mailman/listinfo/gmsh
--
Prof. Christophe Geuzaine
University of Liege, Electrical Engineering and Computer Science
http://www.montefiore.ulg.ac.be/~geuzaine