> On 19 Mar 2015, at 22:23, Sacconi, Andrea <[email protected]> wrote: > > Hi everyone, > > I would like to ask you a very important question about the orientation of > surfaces. It is driving me insane since I get contradictory outputs and I > cannot understand where I am doing wrong. > > The problem is the following: I need to generate a 3D mesh for a > parallelepiped which has a spherical hole inside. Therefore, I have defined > the 6 outer faces and the inner sphere. In order to correctly define the > volume, I need to create two surface loops. I now have to pass the > orientation: which is the correct rule? Inner normal or outer normal? In > other words, clockwise orientation on the outer faces and anticlockwise on > the inner ones or viceversa?
It actually does not matter for the 3D mesh generation algorithms. The one that requires outer orientation (Frontal 3D) reorients them automatically on-the-fly. > I see that I experimentally get two different meshes if I switch from one to > the other. > Second question: for some of my simulations, I need to remesh my domain, > since the hole drifts and the quality of the tetrahedra deteriorates. I > create a surface loop with all the triangular faces the hole is composed of, > but sometimes I get the weird message: "GMSH is not able to orient surface > XXX. Normal computed with 5, 10, ....., 10000 points. Failed". How can I fix > this? Does it depend on the resolution of my mesh? > > I would really appreciate an answer, since I have a deadline for my PhD > thesis, and so far I haven't managed to get these simulations work. > Thank you a lot in advance !!!!!! > Which version of Gmsh do you use? Give the latest version (2.9.1) a try and let us know. Christophe > Andrea > __________________________________________________________ > > Andrea Sacconi > PhD student, Applied Mathematics > AMMP Section, Department of Mathematics, Imperial College London, > London SW7 2AZ, UK > [email protected] > > _______________________________________________ > 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
