Hi Jan, Thanks for the response. Do you have any idea how to fix this issue? Is there some way to precondition the geometry before we begin the meshing process?
On Dec 5, 2013, at 5:09 AM, Jan Blechta wrote: > On Wed, 4 Dec 2013 11:49:23 -0800 > Brian Drawert <[email protected]> wrote: > >> Hello all, >> I am hoping someone can help me. I am having problems when I try to >> use the CSG geometry. I am following the documentation found here: >> http://fenicsproject.org/documentation/dolfin/dev/python/demo/documented/csg-3D/python/documentation.html >> >> I modified the code for my geometry, a cylinder capped by two spheres >> (an e. coli cell): >> >> import dolfin >> # Build CSG Coli using Dolfin. >> pt1 = dolfin.Point(0,0,2.0) >> pt2 = dolfin.Point(0,0,-2.0) >> sphere1 = dolfin.Sphere(pt1,0.5) >> sphere2 = dolfin.Sphere(pt2,0.5) >> cylinder = dolfin.Cylinder(pt1,pt2,0.5) >> g3d = sphere1 + cylinder + sphere2 >> # Generate and plot mesh >> print "Starting meshing..." >> mesh3d = dolfin.Mesh(g3d, 32) >> print "Finished meshing" >> dolfin.info(mesh3d) >> dolfin.plot(mesh3d, "3D mesh") >> dolfin.interactive() >> >> >> When I run this code, it hangs after it prints "Removing triangles > > For me, DOLFIN 1.2.0 and dev do not hang but raises an error > >>>> mesh3d = dolfin.Mesh(g3d, 32) > Converting geometry to cgal types. > Convert to nef polyhedron > Removing degenerated facets > Number of degenerate facets: 343 > Removing triangles with short edges > Traceback (most recent call last): > File "<stdin>", line 1, in <module> > File > "/usr/users/blechta/fenics/fenics-tmp/lib/python2.7/site-packages/dolfin/mesh/meshes.py", > line 68, in __init__ > cpp.Mesh.__cppinit__(self, *args, **kwargs) > File > "/usr/users/blechta/fenics/fenics-tmp/lib/python2.7/site-packages/dolfin/cpp/mesh.py", > line 1572, in __init__ > _mesh.Mesh_swiginit(self,_mesh.new_Mesh(*args)) > StandardError: CGAL ERROR: precondition violation! > Expr: circulator_size(h->vertex_begin()) >= size_type(3) > File: /usr/local/pkg/cgal/4.2/gnu/include/CGAL/Polyhedron_3.h > Line: 1161 > > > Jan > >> with short edges". I have to force quite the process, control-c does >> not terminate it. >> >> $ python demo_csg-3D.py >> Starting meshing... >> Converting geometry to cgal types. >> Convert to nef polyhedron >> Removing degenerated facets >> Number of degenerate facets: 342 >> Removing triangles with short edges >> >> >> Can anyone help? Am I doing something wrong, or is there a bug in >> the meshing code? >> >> Thanks in advance! >> Brian Drawert _______________________________________________ fenics-support mailing list [email protected] http://fenicsproject.org/mailman/listinfo/fenics-support
