[Gmsh] questions on the .msh-file
gdmcbain at freeshell.org
Thu Jan 28 23:21:14 CET 2010
On Thu, Jan 28, 2010 at 8:04 PM, Martin Huber <mhubi87 at gmail.com> wrote:
> I'm currently working on including meshes, consisting only of 3-node
> triangles, from gmsh into a BEM-code. So I have some questions on the
> msh-file that I couldn't find in the manual:
> - In the element section there are not only 3-node triangles, but also
> some nodes and some edges (but as far as I noticed not all of them). Are
> these special nodes/edges and why are they in the elements section?
They're not necessarily special, just artifacts from how the geometry
was defined: `elementary geometric entities'. You can suppress them
and just output the three-node triangular elements by defining the
surface they lie on as a `Physical Surface'
<http://geuz.org/gmsh/doc/texinfo/gmsh.html#Surfaces>; for the
distinction between `elementary' and `physical' entities in Gmsh, see
> - Is it possible to get information about neighbourhood of the
> triangles, e.g. an additional array that tells, which triangle is beside
> the edge number i of the current triangle?
This is harder. I don't know how to do it in Gmsh, or whether it's possible.