Hi Paul, Apparently we broke this (again) in 2.6. (It works fine in 2.5.)
We will investigate. Thanks for the report, Christophe On 25 Oct 2012, at 17:44, Paul Cristini <[email protected]> wrote: > Hello all, > > I am just trying to do the extrusion of a spline and depending on the > position of a point of the spline I got 2 elements with a negative jacobian. > > Here is the .geo file. If Point(3) = { -L/2, l+dl/2, 0, lc}; is changed to > Point(3) = { -L/2, l+dl/3, 0, lc}; ,which means that one point is lowered, > then no problem. > > I am generating all quads meshes and I am also using second order elements. > I noticed that if I use first order or incomplete second order element there > is no element with a negative jacobian. > > Any idea of what's going on ? > > Thanks > > Paul > > // Gmsh project created on Sat Apr 10 19:26:34 2010 > lambda = 30; > lc=lambda/4; > // > L = 10 * lambda; // Width > l = 8 * lambda; // Height > dl = 2 * lambda; // Decalage > > Point(1) = { L, l+dl, 0, lc}; > Point(2) = {-L, l, 0, lc}; > // > Point(3) = { -L/2, l+dl/2, 0, lc}; > Point(4) = { 0, l+dl/3, 0, lc}; > Point(5) = { L-L/4, l+dl/2, 0, lc}; > > //lx1 = newl; Line(lx1) = {cx2, cx1}; > lx1 = newl; Spline(lx1) = {2, 3, 4, 5, 1}; > Extrude {0,1.5*lambda,0} {Line{lx1}; Layers{3};Recombine; }; > > -- > *--------------------------------------------------------------------------* > Paul CRISTINI Charge de Recherche CNRS / CNRS Research Scientist > -------- > CNRS - Laboratoire de Mecanique et d'Acoustique (UPR 7051) > > 31 chemin Joseph Aiguier, F-13402 Marseille Cedex 20 - France > mailto: [email protected] > phone number: +33 (0)4 91 16 42 89 > fax number: +33 (0)4 91 16 44 81 > http://www.lma.cnrs-mrs.fr/ > *--------------------------------------------------------------------------* > > > _______________________________________________ > gmsh mailing list > [email protected] > http://www.geuz.org/mailman/listinfo/gmsh -- Prof. Christophe Geuzaine University of Liege, Electrical Engineering and Computer Science http://www.montefiore.ulg.ac.be/~geuzaine _______________________________________________ gmsh mailing list [email protected] http://www.geuz.org/mailman/listinfo/gmsh
