[Gmsh] topography issues

[Riad HASSANI]

Hi Octavio,

here is in a zip file three very simple examples. 

For clarity, I also attached my little fortran program that reads a 2D mesh, interpolates the topography and smoothes the mesh of some faces. 
Please, see the header of this program for a commented example.

Best,
Riad


Le 24 oct. 2018 à 19:11, Octavio Castillo Reyes <ocastilloreyes at gmail.com> a écrit :

> Dear Riad, 
> 
> I'm trying to reproduce your strategy. Until now, I have the topography layer (see attached image). However, I'm having troubles to define and close the volume... Can you share with me your *.geo script? How do you merge the 2D surface with other flat surfaces in order to close the volume?
> 
> Thank you for your time and support. 
> 
> best regards
> 
> O.
> 
> On Tue, Sep 25, 2018 at 2:42 PM Octavio Castillo Reyes <ocastilloreyes at gmail.com> wrote:
> Yes, thank you! 
> 
> This will be very useful to me. I will try to apply it to a real case and I will tell you
> 
> Best regards
> 
> O.
> 
> On Tue, Sep 25, 2018 at 1:04 PM Riad HASSANI <Riad.Hassani at unice.fr> wrote:
> Hi Octávio,
> I'm not sure I understood your question correctly. 
> Is that the kind of thing you want to do? (if yes, the procedure works well):
> 
> Best,
> Riad
> 
> Le 21 sept. 2018 à 12:52, Octavio Castillo Reyes <ocastilloreyes at gmail.com> a écrit :
> 
>> Dear all, 
>> 
>> I'm interested too. My domains are composed 3, 4 or 5 materials (maybe more) where each interface might include a topography. For instance, do you know if is possible include another layer to the model proposed by Riad Hassani?
>> 
>> Any idea?
>> 
>> Best regards
>> 
>> O.
>> 
>> On Fri, Sep 21, 2018 at 12:37 PM Riad HASSANI <Riad.Hassani at unice.fr> wrote:
>> Hi Stephanie,
>> 
>> the only trick I had found at the time is in three steps (there may be more direct solutions, if so, I'm interested!):
>> 
>> 1) mesh only the "skin" of your domain (2D mesh), save it in a .msh file
>> 2) move the nodes of the surface to match with your topography (use an external program that reads the .msh, interpolates the topography on the appropriate faces and rewrites your .msh).
>> 3) in a .geo file, merge this new .msh, define the volume and then mesh it (3D mesh) (for example, if the initial domain has 6 faces : Merge "skin_modified.msh"; Surface Loop(1) = {1,2,3,4,5,6}; Volume(1)={1}; )
>> 
>> Best,
>> 
>> Riad
>> 
>> 
>> 
>> Le 21 sept. 2018 à 02:12, Stephanie Jarvis <Stephanie.Jarvis at colorado.edu> a écrit :
>> 
>>> Hello,
>>> 
>>> Can gmsh can handle topography? I see this has been asked several times but I can't find a resolution. I have surveyed grid points from a hillslope surface that I need to create a 3D mesh for (top of the box is the hillslope topography, bottom is flat extending into the surface). I've tried embedding the points into a surface I create around them, using Point In Surface, but the points mesh as holes (if they're below that surface) or in the air by themselves (if they're above)--there is no interpolation between them. I've also tried several variations of lines and splines connecting the points, but I can't get that to mesh successfully. Plugin(Tetrahedralize) looks promising, but it's unclear to me how to use it--is it possible to get a "View" out of a bunch of points?  Or do I need to create an interpolated surface outside of gmsh and bring that in to mesh?
>>> 
>>> Thank you!
>>> Stephanie
>>> _______________________________________________
>>> gmsh mailing list
>>> gmsh at onelab.info
>>> http://onelab.info/mailman/listinfo/gmsh
>> 
>> -----------------------------------------------------------------
>> Riad HASSANI
>> GéoAzur
>> Université Nice-Sophia Antipolis
>> 250 rue Albert Einstein
>> Sophia Antipolis
>> 06560 Valbonne - France
>> tel. : 33 (0) 4 83 61 86 71 / 33 (0) 4 92 07 65 89
>> 
>> 
>> 
>> 
>> 
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>> gmsh mailing list
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> 
> -----------------------------------------------------------------
> Riad HASSANI
> GéoAzur
> Université Nice-Sophia Antipolis
> 250 rue Albert Einstein
> Sophia Antipolis
> 06560 Valbonne - France
> tel. : 33 (0) 4 83 61 86 71 / 33 (0) 4 92 07 65 89
> 
> 
> 
> 
> 
> <topography.png>

-----------------------------------------------------------------
Riad HASSANI
GéoAzur
Université Nice-Sophia Antipolis
250 rue Albert Einstein
Sophia Antipolis
06560 Valbonne - France
tel. : 33 (0) 4 83 61 86 71 / 33 (0) 4 92 07 65 89





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