dolfin team mailing list archive

["Garth N. Wells" <gnw20@xxxxxxxxx>]

On 16 March 2012 09:17, Johan Hake <hake.dev@xxxxxxxxx> wrote:
> Hello!
>
> I have implemented a new version of UnitSphere based on subdivision of an
> initial octahedral surface mesh and tetrahedralization using the CGAL
> framework.
>
> This is all fine, but CGAL uses alot of time tetrahedralizing the initial
> surface mesh. CGAL is also doing some funny things with the surface mesh.
>
>  1) It subdivide the initial surface mesh, which I want to prevent. Is
>     that possible.
>  2) 1) results in small triangles on the surface, but large triangles
>     in the interior. I set a tentative volume constraint based on the
>     size of a triangle of the input mesh.
>
> You can try it out here:
>
>  bzr branch lp:~dolfin-core/dolfin/hake-trunk
>
>  from dolfin import *
>  mesh = UnitSphereNew(4)
>  # Do not try larger subdivisions than 4, at least for now.
>

Did you look at the CGAL demo for generating a mesh or a sphere:

   http://www.cgal.org/Manual/latest/doc_html/cgal_manual/Mesh_3/Chapter_main.html#Subsection_50.3.1

? It uses an implicit surface description. I has planning to add
support for meshing geometries from implicit descriptions.

Garth

>
> Johan
>
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