[Gmsh] Question about Gmsh

Zenker, Dr. Matthias Matthias.Zenker at erbe-med.com
Mon Nov 12 10:12:38 CET 2012


Hi,

if you just want simulation results at defined points in space, you could also try to use interpolation in your postprocessing process.

HTH,

Matthias


> -----Ursprüngliche Nachricht-----
> Von: David Colignon [mailto:David.Colignon at ulg.ac.be]
> Gesendet: Freitag, 9. November 2012 16:00
> An: youngjun at mail.ustc.edu.cn; gmsh at geuz.org
> Betreff: Re: [Gmsh] Question about Gmsh
>
>
> On 08/11/12 15:04, youngjun at mail.ustc.edu.cn wrote:
>
> > Hi, David,
> >
> > Thank you for the advice.
> >
> > The method did work for plane surface, but when the model contains
> topography, problem comes again. I have to define the curved surface first
> with GPS data, and then embed the detecting points in the surface. If I still
> use the command Point | Line { expression-list } In Surface { expression };, it
> doesn't create a surface with topography.
> >
> > So the problem is the same as mentioned in my last email: If I have a large
> number of control points(like GPS data), is there a simple way to create a
> surface with topography using these points?
>
> Hi,
>
> do you know about the "Triangulate" plug-in ?
>
> Plugin(Triangulate) triangulates the points in the view `View', assuming that
> all the points belong to a surface that can be projected one-to-one onto a
> plane.
> If `View' < 0, the plugin is run on the current view.
> Plugin(Triangulate) creates one new view.
>
> and the corresponding "Tetrahedralize" plug-in ?
>
> Plugin(Tetrahedralize) tetrahedralizes the points in the view `View'.
> If `View' < 0, the plugin is run on the current view.
> Plugin(Tetrahedralize) creates one new view.
>
> >
> > By the way, is there a command or combined technique to embed points in
> a volume like the one for surface?
>
> No, it is much more difficult to implement in the 3D meshing algorithms than
> in the 2D's
>
> Regards,
>
> Dave
>
>
> >
> > Best Regards,
> >
> > Jun Yang
> >
> >
> >
> >> -----Original E-mail-----
> >> From: "David Colignon" <David.Colignon at ulg.ac.be> Sent Time:
> >> 2012-11-8 17:40:25
> >> To: youngjun at mail.ustc.edu.cn
> >> Cc: gmsh at geuz.org
> >> Subject: Re: [Gmsh] Question about Gmsh
> >>
> >> Hi,
> >>
> >> did you see or try this:
> >>
> >> https://geuz.org/gmsh/doc/texinfo/gmsh.html#Miscellaneous-mesh-
> comman
> >> ds
> >>
> >> Point | Line { expression-list } In Surface { expression };
> >>
> >>       Embed the point(s) or line(s) in the given surface. The surface
> >> mesh will conform to the mesh of the point(s) or lines(s). Note that
> embedded lines only work with the MeshAdapt 2-D algorithm.
> >>
> >>
> >> Regards,
> >>
> >> Dave
> >>
> >> --
> >> David Colignon, Ph.D.
> >> Collaborateur Logistique du F.R.S.-FNRS CÉCI - Consortium des
> >> Équipements de Calcul Intensif ACE - Applied & Computational
> >> Electromagnetics Université de Liège Sart-Tilman B28 10, Grande
> >> Traverse
> >> 4000 Liège - BELGIQUE
> >> Tél: +32 (0)4 366 37 32
> >> WWW:    http://www.ceci-hpc.be/
> >> Agenda:
> >>
> http://www.google.com/calendar/embed?src=david.colignon%40gmail.com
> >>
> >> On 08/11/12 05:56, youngjun at mail.ustc.edu.cn wrote:
> >>> Dear Professor Christophe Geuzaine and Professor Jean-François
> >>> Remacle,
> >>>
> >>> I'm a graduate student from University of Science and Technology of
> China. My major is geophysics and I am now using Gmsh to build models for
> modeling geoeletric field.
> >>>
> >>> These models are quite simple. The structure of the model is a cuboid
> space with some simple bodies whose properties differ from the cuboid
> space(We call them anomalies) inside it. Then when I try to specify large
> amount of points that regularly spread on the surface of the model for
> measuring the eletric potential, it seems that it's not going to be an easy task.
> I have to define all these points, then create line segments between every
> two adjacent points, followed by forming line loops to define plane surfaces,
> and finally put them into a part of the volume in order to execute the 3D
> mesh. If I don't do it in this way, the produced grid will have nothing to do
> with these deteting points. However, I need to make sure that these points
> on the surface are nodes of the elements.
> >>>
> >>> So is there an easy technique to accomplish this operation? More
> generally, is there an elementary classification for stand-alone control points
> which is going to be the nodes of the elements when execute the mesh
> operation, like the ones I described above? I'm not sure if I miss some
> important information in the Gmsh Reference Manual, but till now I can't find
> a simple way.
> >>>
> >>> The attachment is the .geo file that describes the model I want to build.
> Only the points, and lines are defined in the file. If these elementaries have
> to be defined manually, thousands of operations are needed.
> >>>
> >>> The Gmsh with GUI is quite easy to operate. Thanks for offering us this
> excellent software!
> >>>
> >>> Best Regards,
> >>> Jun Yang
> >>> University of Scinece and Technology of China Heifei,China
> >>> Email: youngjun at mail.ustc.edu.cn
> >>>
> >>>
> >>>
> >>> _______________________________________________
> >>> gmsh mailing list
> >>> gmsh at geuz.org
> >>> http://www.geuz.org/mailman/listinfo/gmsh
> >>>
> >>
> >
>
>



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