CGAL users discussion list

[Andreas Fabri <>]

Dear Jehyun,

With not successful, you probably mean that the mesh
generator did not produce any mesh.

The problem is that the mesh generator does not construct
a good enough initial point set. The current strategy is to
shoot rays in random directions from the center of the bounding
box of your object.  We will provide a solution next
week, as we are extremely busy this week.  Either a random
sample of points on the surface, or random rays shooted from
the points on the skeleton will do the job. This is only
not provided by the current API.

We can't do anything on respecting your input constraints,
as we do not have a 3D Constrained Delaunay triangulation
algorithm.

What is the license of the data set? Would you allow that we
distribute it together with CGAL?

Best regards,

Andreas

On 16/03/2016 03:22, Jehyun Cha wrote:
> I'm trying to triangulate given coronary artery model(please refer image and
> file).
>
> At first, I've tried to triangulate them using 3D constrained Delaunay
> triangulation in TetGen engine, but it appears that TetGen didn't generate
> them in all time. I've tried about 40 models with closed boundary, but only
> half of them was successful.
>
> As an alternative, I found that CGAL 3D mesh generation will generate
> similar mesh based on Delaunay triangulation(of course, it's different from
> 3D constrained Delaunay triangulation).
>
> I also tested it for 40 models which is same dataset used in TetGen test,
> but it appears that only 1/4 of them were successful. It is weird because
> even less models were processed than in TetGen test.
>
> Is there are any condition for CGAL mesh generation except closed manifold
> condition(no boundary & manifold)? Here is the code I've used in my test
> case. It is almost same to example code from CGAL website.
>
> ========================================================
> // Create input polyhedron
> Polyhedron polyhedron;
> std::ifstream input(fileName.str());
> input >> polyhedron;
>
> // Create domain
> Mesh_domain domain(polyhedron);
>
> // Mesh criteria (no cell_size set)
> Mesh_criteria criteria(facet_angle = 25, facet_size = 0.15, facet_distance =
> 0.008,
>      cell_radius_edge_ratio = 3);
>
> // Mesh generation
> C3t3 c3t3 = CGAL::make_mesh_3<C3t3>(domain, criteria, no_perturb(),
> no_exude());
> cout << "Polygon finish: " << c3t3.number_of_cells_in_complex() << endl;
> =========================================================
>
> Here is  one of CA model
> <https://drive.google.com/file/d/0B81xvhk118U8VHdJTnM5amVmUVk/view?usp=sharing>
> which was used in test case.
>
> Also, I want to preserve given model triangles in generated mesh like
> constrained Delaunay triangulation. Is there are any way that generate mesh
> without specific criteria?
>
> Please let me know if you want to know more.
>
>
>
> --
> View this message in context: 
> http://cgal-discuss.949826.n4.nabble.com/CGAL-3D-mesh-generation-prerequisite-condition-tp4661693.html
> Sent from the cgal-discuss mailing list archive at Nabble.com.

--
Andreas Fabri, PhD
Chief Officer, GeometryFactory
Editor, The CGAL Project

phone: +33.492.954.912    skype: andreas.fabri