[Gmsh] Getting lines' nodes
Dear all,
Is there a way to fetch curves' (lines' in particular) points? Something
like:
c[] = Point{1}; // c[] contains the coordinates 1,2,3
which is used to get point's coordinates, but I would need lines' points.
Kind regards
Bojan
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Re: [Gmsh] Points seem to move on transfinite surface after the recombination
Dear Christophe,
Oh great, thanks a lot for the fast reply :-)
Best regards,
Bojan
On Wed, Jul 8, 2020 at 1:08 PM Christophe Geuzaine
wrote:
>
>
> > On 8 Jul 2020, at 12:46, Bojan Niceno
> wrote:
> >
> > Dear all,
> >
> > I have a problem when trying to mesh planar structured surfaces.
> Although points seem to be uniformly placed on a transfinite surface, they
> move a bit when recombining the mesh to change triangles to quadrilateral
> cells.
> >
> > Here is a simple script which demonstrates it:
> >
> > // Define points
> > Point(1) = {0.0, 0.0, 0.0};
> > Point(2) = {0.5, 0.0, 0.0};
> > Point(3) = {0.0, 0.5, 0.0};
> > Point(4) = {0.7, 0.0, 0.0};
> > Point(5) = {0.0, 0.7, 0.0};
> >
> > // Define connectors from points ...
> > Line (1) = {2, 4};
> > Circle(2) = {4, 1, 5};
> > Line (3) = {5, 3};
> > Circle(4) = {3, 1, 2};
> >
> > // ... and set them as transfinite
> > Transfinite Curve {1, 2, 3, 4} = 11 Using Progression 1;
> >
> > // Define surface ...
> > Curve Loop(1) = {1, 2, 3, 4}; Plane Surface(1) = {1};
> >
> > // ... and set it as transfinite too
> > Transfinite Surface {1};
> >
> > So, as I said, generating a 2D mesh over the surface places points
> properly, but command recombine moves them a bit :-/ Is there a way to
> prevent these movements of points?
> >
> > I am also attaching a screenshot of a mesh before and after
> recombination, to illustrate my problem better.
> >
>
> Indeed, recombination a posteriori applies some smoothing. You should add
>
> Recombine Surface{1};
>
> after "Transfinite Surface {1};", which will directly create a quad mesh.
>
> Christophe
>
>
>
>
> > Best regards,
> >
> > Bojan
> >
> > P.S. I am not sure if attachments go to the mailing list, I've never
> used a mailing list before.
> >
> >
> ___
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>
> —
> Prof. Christophe Geuzaine
> University of Liege, Electrical Engineering and Computer Science
> http://www.montefiore.ulg.ac.be/~geuzaine
>
>
>
>
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Re: [Gmsh] Unable to select surfaces using GUI
> On 6 Jul 2020, at 21:51, A Chaube wrote: > > Hello, > > I have a complicated 2D mesh with lots of elements (which I cannot reduce in > number), and I am extruding this into a 3D mesh. Upon extrusion, it becomes > extremely challenging to keep track of new surfaces (needed for creating > sidesets) - the easiest way seems to be to select them using the GUI. > > However, the geometry model has no opacity for surfaces (just a wireframe > marker), so everything looks really busy and it is impossible to click on the > surface that I wish to select. Making mesh elements visible makes the model > visually opaque and less busy, but some surface markers (the dotted crosses) > simply disappear, making it impossible to select the right surface without a > lot of effort (tracking common curves to deduce surface ID etc). > > Could you please suggest a way to select physical surfaces when you have lots > of different surfaces (12-20 per physical surface, and about 10 physical > surfaces)? You could use Tools->Visibility to hide/show only parts of the model, or Tools->Clipping. Once you have a mesh you can also only display mesh edges, which will allow to "see through". Christophe > > Thank you. > Ash. > ___ > gmsh mailing list > gmsh@onelab.info > http://onelab.info/mailman/listinfo/gmsh — Prof. Christophe Geuzaine University of Liege, Electrical Engineering and Computer Science http://www.montefiore.ulg.ac.be/~geuzaine ___ gmsh mailing list gmsh@onelab.info http://onelab.info/mailman/listinfo/gmsh
Re: [Gmsh] Points seem to move on transfinite surface after the recombination
> On 8 Jul 2020, at 12:46, Bojan Niceno
> wrote:
>
> Dear all,
>
> I have a problem when trying to mesh planar structured surfaces. Although
> points seem to be uniformly placed on a transfinite surface, they move a bit
> when recombining the mesh to change triangles to quadrilateral cells.
>
> Here is a simple script which demonstrates it:
>
> // Define points
> Point(1) = {0.0, 0.0, 0.0};
> Point(2) = {0.5, 0.0, 0.0};
> Point(3) = {0.0, 0.5, 0.0};
> Point(4) = {0.7, 0.0, 0.0};
> Point(5) = {0.0, 0.7, 0.0};
>
> // Define connectors from points ...
> Line (1) = {2, 4};
> Circle(2) = {4, 1, 5};
> Line (3) = {5, 3};
> Circle(4) = {3, 1, 2};
>
> // ... and set them as transfinite
> Transfinite Curve {1, 2, 3, 4} = 11 Using Progression 1;
>
> // Define surface ...
> Curve Loop(1) = {1, 2, 3, 4}; Plane Surface(1) = {1};
>
> // ... and set it as transfinite too
> Transfinite Surface {1};
>
> So, as I said, generating a 2D mesh over the surface places points properly,
> but command recombine moves them a bit :-/ Is there a way to prevent these
> movements of points?
>
> I am also attaching a screenshot of a mesh before and after recombination, to
> illustrate my problem better.
>
Indeed, recombination a posteriori applies some smoothing. You should add
Recombine Surface{1};
after "Transfinite Surface {1};", which will directly create a quad mesh.
Christophe
> Best regards,
>
> Bojan
>
> P.S. I am not sure if attachments go to the mailing list, I've never used a
> mailing list before.
>
> ___
> gmsh mailing list
> gmsh@onelab.info
> http://onelab.info/mailman/listinfo/gmsh
—
Prof. Christophe Geuzaine
University of Liege, Electrical Engineering and Computer Science
http://www.montefiore.ulg.ac.be/~geuzaine
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