On 16 March 2012 12:49, Johan Hake <[email protected]> wrote: > On 03/16/2012 10:28 AM, Garth N. Wells wrote: >> >> On 16 March 2012 09:17, Johan Hake<[email protected]> 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. > > > No I didn't. Are we using the implicit interface in dolfin? >
Not yet, but I will add an interface for it, > Using a subdivision algorithm is probably the fastest and cleanest way to > generate the surface of a Sphere. Using an implicit function might create > surfaces which does not follow the input mesh, which is what I want. > What you you mean? The mesh will conform to the true surface to within a specified tolerance. What the implicit representation has trouble is with sharp edges. Garth > johan > > >> Garth >> >>> >>> Johan >>> >>> _______________________________________________ >>> Mailing list: https://launchpad.net/~dolfin >>> Post to : [email protected] >>> Unsubscribe : https://launchpad.net/~dolfin >>> More help : https://help.launchpad.net/ListHelp > > _______________________________________________ Mailing list: https://launchpad.net/~dolfin Post to : [email protected] Unsubscribe : https://launchpad.net/~dolfin More help : https://help.launchpad.net/ListHelp
