CGAL users discussion list

[Sebastien Loriot <>]

There is no better solution that iterating over cells in the complex
and using a std::set/std:unordered to track already seen vertices.

Best,

Sebastien.

On 5/12/22 17:50, Bob Bill ( via cgal-discuss Mailing 
List) wrote:
> Sorry for posting again, but I have a related question about this: how 
> can I get all the vertices inside the domain? So far the only way I can 
> come up with is to use `cells_in_complex_begin()` and get each vertex by 
> looping over each tetrahedron, like the following:
>
> for(auto iter = c3t3.cells_in_complex_begin(); 
> it!=c3t3.cells_in_complex_end();++it){
>      for(int j=0;j<4;++j) auto p = it->vertex(j)->point();
> }
>
> Of course by doing this way there'll be a lot of duplication and I'd 
> have to use an std::set.
>
> Is there some other way to do this?
>
> Best,
> Bob
>
>
> Il martedì 10 maggio 2022, 15:55:52 CEST, Bob Bill <> 
> ha scritto:
>
>
> Here's the link to the minimal working example on Gist: 
> https://gist.github.com/boblukas/603c16f4aceca0d7a5b46fa8150fae29 
> <https://gist.github.com/boblukas/603c16f4aceca0d7a5b46fa8150fae29> (The 
> cube.off is taken from CGAL repo: 
> https://github.com/CGAL/cgal/blob/master/Data/data/meshes/cube.off 
> <https://github.com/CGAL/cgal/blob/master/Data/data/meshes/cube.off> )
> The output shows 52 cells, which are way too many for my application.
>
>
> Thanks a lot for your time,
> Bob
> Il martedì 10 maggio 2022, 15:27:41 CEST, Sebastien Loriot" 
> ( via cgal-discuss Mailing List) 
> <> ha scritto:
>
>
> The number of input triangles does no affect the number of output cells.
>
> Note that a simple working example that we can compile and run on
> gist.github.com would most probably understand your problem.
> Right now I can only guess that the number of output cells is the one
> needed to preserve the topological criteria.
>
> Best,
>
> Sebastien.
>
> On 5/10/22 15:23, Bob Bill ( 
> <> via cgal-discuss Mailing
> List) wrote:
>  > Unfortunately the result is more or less the same, but I think I
>  > identified the issue: my original surface mesh is not triangulated, so
>  > maybe CGAL::triangulate_faces() is adding  too many triangles, right?
>  > The following snippet highlights what I am referring to. Is there any
>  > way to have a "minimal" triangulation for the faces when calling
>  > triangulate_faces()?
>  >
>  > Best,
>  > Bob
>  >
>  > CGAL::Polygon_mesh_processing::triangulate_faces(surface_mesh);
>  > Mesh_domain domain(surface_mesh);
>  > domain.detect_features();
>  > Mesh_criteria criteria(CGAL::parameters::facet_size = 0,
>  > CGAL::parameters::facet_distance = 0,
>  > CGAL::parameters::cell_radius_edge_ratio = 2,
>  > CGAL::parameters::cell_size = 0);
>  > C3t3 triangulation = CGAL::make_mesh_3<C3t3>(domain,
>  > criteria,
>  > CGAL::parameters::no_perturb(),
>  > CGAL::parameters::no_exude());
>  >
>  > Il martedì 10 maggio 2022, 09:29:46 CEST, Sebastien Loriot"
>  > ( <> via cgal-discuss 
> Mailing List)
>  > < <>> ha scritto:
>  >
>  >
>  > If you put facet_size=0, facet_distance=0, cell_radius_edge_ratio=2 and
>  > cell_size=0 then there is no geometric criteria applied to refine the
>  > mesh (only the topological one). If you mesh is too coarse then you
>  > can change those values to match the level of detail you are expecting.
>  >
>  > Best,
>  >
>  > Sebastien.
>  >
>  > On 5/9/22 14:51, Bob Bill ( 
> <>
>  > < <>> via 
> cgal-discuss Mailing
>  > List) wrote:
>  >  > Dear all,
>  >  >
>  >  > I successfully applied the function make_mesh_3() to fill a 3D 
> mesh. So
>  >  > far the result is too refined, and I'd like to let my C3t3 to be as
>  >  > coarse as possible, i.e. I want only few tets inside.
>  >  >
>  >  > If I use the default constructor
>  >  >
>  >  > Mesh_criteria criteria;
>  >  >
>  >  > then the result is non-sense. Is there any way to have something like
>  >  > the bottom left figure here
>  >  > 
> (https://doc.cgal.org/latest/Mesh_3/index.html#fig__figureparameters 
> <https://doc.cgal.org/latest/Mesh_3/index.html#fig__figureparameters >
>  > <https://doc.cgal.org/latest/Mesh_3/index.html#fig__figureparameters 
> <https://doc.cgal.org/latest/Mesh_3/index.html#fig__figureparameters>>) ,
>  >  > but without specifying the parameters for every situation?
>  >  >
>  >  > Bob
>  >  >
>  >  > --
>  >  > You are currently subscribed to cgal-discuss.
>  >  > To unsubscribe or access the archives, go to
>  >  > https://sympa.inria.fr/sympa/info/cgal-discuss 
> <https://sympa.inria.fr/sympa/info/cgal-discuss >
>  > <https://sympa.inria.fr/sympa/info/cgal-discuss 
> <https://sympa.inria.fr/sympa/info/cgal-discuss>>
>
>  >
>  >  >
>  >
>  > --
>  > You are currently subscribed to cgal-discuss.
>  > To unsubscribe or access the archives, go to
>  > https://sympa.inria.fr/sympa/info/cgal-discuss 
> <https://sympa.inria.fr/sympa/info/cgal-discuss >
>  > <https://sympa.inria.fr/sympa/info/cgal-discuss 
> <https://sympa.inria.fr/sympa/info/cgal-discuss>>
>  >
>  >
>  >
>  > --
>  > You are currently subscribed to cgal-discuss.
>  > To unsubscribe or access the archives, go to
>  > https://sympa.inria.fr/sympa/info/cgal-discuss 
> <https://sympa.inria.fr/sympa/info/cgal-discuss>
>  >
>
> --
> You are currently subscribed to cgal-discuss.
> To unsubscribe or access the archives, go to
> https://sympa.inria.fr/sympa/info/cgal-discuss 
> <https://sympa.inria.fr/sympa/info/cgal-discuss>
>
>
>
> --
> You are currently subscribed to cgal-discuss.
> To unsubscribe or access the archives, go to
> https://sympa.inria.fr/sympa/info/cgal-discuss