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[Sebastien Loriot <>]

Sorry for the late reply.

Unfortunately, you won't be able to get much less that 52 cells.
In this particular case, you have some vertices on edges added so
that they are in the output and then initialization (some points
thrown in the domain). For this particular case, we could probably
not add any extra initialization points thanks to protected edges
but in general this step is essential to get a valid initial
triangulation to be refined.

Maybe what you need is more something like a 3D constrained Delaunay
triangulation that CGAL does not provide yet.

Best,

Sebastien.

On 5/10/22 15:55, Bob Bill ( via cgal-discuss Mailing 
List) wrote:
> 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
>  >  >
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