<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">David is right, and sure maybe we should automatically optimize 3D delaunay meshes<div><br></div><div>JF</div><div><br><div><div>Le 25-août-10 à 20:53, David Colignon a écrit :</div><br class="Apple-interchange-newline"><blockquote type="cite"><div><br><br>On 25/08/10 19:12, 류은현 wrote:<br><blockquote type="cite">Before asking, Thank you for your kind answer about my preivous question.<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">It was so helpful to me.<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">I am working on developing 3D FEM application related with neutronics problem.<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">Following is my first question<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">Today I made 3D domain, that has physical volumes. But I saw that the jacobian of certain element is zero.<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">Because of a element that is consist of 4 nodes which are located on same plane!<br></blockquote><br><br>Hi,<br><br>Did you try the Tools->Options->Mesh->Advanced->"Optimize quality of tetrahedra" option ?<br><br><blockquote type="cite"><br></blockquote><blockquote type="cite">Why does GMSH produce such a strange element? Does it due to my fault in making GMSH input?<br></blockquote><br><br>Impossible to answer without your .geo file ...<br><br>regards,<br><br>Dave<br><br><br><br>--<br>David Colignon, Ph.D.<br>Collaborateur Logistique du F.R.S.-FNRS<br>CÉCI - Consortium des Équipements de Calcul Intensif<br>ACE - Applied & Computational Electromagnetics<br>Institut Montefiore B28<br>Université de Liège<br>4000 Liège - BELGIQUE<br>Tél: +32 (0)4 366 37 32<br>Fax: +32 (0)4 366 29 10<br>WWW: <a href="http://hpc.montefiore.ulg.ac.be/">http://hpc.montefiore.ulg.ac.be/</a><br>Agenda: <a href="http://www.google.com/calendar/embed?src=david.colignon%40gmail.com">http://www.google.com/calendar/embed?src=david.colignon%40gmail.com</a><br><br><br><blockquote type="cite"><br></blockquote><blockquote type="cite">Of course, I can eliminate that element by giving certain condition to my code, it seems to be strange.<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">Please tell me in detail, if the reason is related with my input.<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">My second question is associated with defining volume. I understood that the orientation of surfaces which will<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">constitute the volume should be consistent. But if we want to make a cube or hexahedron volume, the following order of<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">surface index is OK? I mean that writing index(upper plane), index(lower plane), index(left plane),.... , not continuously.<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">Please tell me in detail. Sorry for bothering you.<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">_______________________________________________<br></blockquote><blockquote type="cite">gmsh mailing list<br></blockquote><blockquote type="cite"><a href="mailto:gmsh@geuz.org">gmsh@geuz.org</a><br></blockquote><blockquote type="cite"><a href="http://www.geuz.org/mailman/listinfo/gmsh">http://www.geuz.org/mailman/listinfo/gmsh</a><br></blockquote><br><br>_______________________________________________<br>gmsh mailing list<br><a href="mailto:gmsh@geuz.org">gmsh@geuz.org</a><br>http://www.geuz.org/mailman/listinfo/gmsh<br></div></blockquote></div><br><div> <span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: medium; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><div><span class="Apple-style-span" style="font-size: medium; "><div>------------------------------------------------------------------</div><div><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px; ">Prof. Jean-Francois Remacle</span></font></div><div><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px; ">Universite catholique de Louvain (UCL)</span></font></div><div><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px; ">Ecole Polytechnique de Louvain (EPL) - Louvain School of Engineering</span></font></div><div><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px; ">Institute of Mechanics, Materials and Civil Engineering (iMMC)</span></font></div><div><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px; ">Center for Systems Engineering and Applied Mechanics (CESAME)</span></font></div><div><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px; ">Tel : +32-10-472352 -- Mobile : +32-473-909930 </span></font></div><div><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px; "><br></span></font></div><div><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px; "> </span></font></div><div><font class="Apple-style-span" size="3"><span class="Apple-style-span" style="font-size: 12px; "><br></span></font></div><div><br></div></span></div></div></div></span></div><br class="Apple-interchange-newline"></div></div></span><br class="Apple-interchange-newline"> </div><br></div></body></html>