[Gmsh] Warnings when 3D mesh ...

Catalin Bondrea cbondrea at robotics.ucv.ro
Wed Jun 11 17:54:10 CEST 2003


I try already this. But in my final geo file looks like will don't work
properly. I add more elements (line surfaces and volumes).
I still have problems with warnings in the messages console. The warnings
looks like Coplanar ...
But I'm sure no coplanar surfaces, if the file code2.geo don't generate
errors, I search all the code. No coplanar surfaces. (I hope!)
The problem is if I will decrease to much the characteristic length (small
number for characteristic length) I will
have to many tetrahedral elements, and my colleges don't want to many.
And if I change the characteristic length factor is what I will do, increase
the number of elements.

If I put the characteristic length bigger than the small length used, the
gmsh generate the 3D mesh, without warnings, but the mesh is not good.
If I put the characteristic length smaller than the small length used, the
gmsh don't generate the 3D mesh, with warnings, and the gmsh looks like
putting a lot of warnings and don't finish the mesh.

Any idea, different than the last?


----- Original Message -----
From: "Christophe Geuzaine" <geuzaine at acm.caltech.edu>
To: "Catalin Bondrea" <cbondrea at robotics.ucv.ro>
Cc: "GMSH" <gmsh at geuz.org>
Sent: Wednesday, June 11, 2003 4:11 PM
Subject: Re: [Gmsh] Warnings when 3D mesh ...


> Catalin Bondrea wrote:
> >
> > Now looks again in the same way like before but when I try to mesh this
> > geo file I have a lot of errors.
> >
> > What is the problem?
>
> Catalin - the 3D algorithm is not very robust when you specify
> characteristic lengths that are larger than the "size" of the
> geometrical entities you want to mesh.
>
> Try for example:
>
> gmsh code1.geo -clscale 0.4
> gmsh code2.geo -clscale 0.4
>
> This multiplies all the characteritic lengths in your model by 0.4.
> You can of course also directly modify your point definitions, use the
> "Mesh.CharacteristicLengthFactor" option, or change the option in the
> GUI (Tools:Options:Mesh:General:Characteristic length factor).
>
> Cheers,
>
> Christophe
>
> --
> Christophe A. Geuzaine
> Applied and Computational Mathematics, Caltech
> geuzaine at acm.caltech.edu - http://geuz.org