<html><head><meta http-equiv="Content-Type" content="text/html charset=iso-8859-1"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><br></div>Hi Johannes,<div><br></div><div>That's weird - it seems to work fine over here (cf screenshot). I will test it on our Linux machine when I have the time.</div><div><br></div><div>Does it happen with all the triangulation methods (MeshAdapt, Delaunay, Frontal, Delaunay for quads)?</div><div><br></div><div><br></div><div>Christophe</div><div><img id="3a59c91a-7926-4974-b666-51aae2148d24" height="837" width="958" apple-width="yes" apple-height="yes" src="cid:F9707876-AE42-4A69-AA24-39EF6CD4F4CC@ulg.ac.be"></div><div><br><div><div>On 13 Mar 2013, at 13:32, Johannes Reinhardt <<a href="mailto:johannes.reinhardt@unifr.ch">johannes.reinhardt@unifr.ch</a>> wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite">Hello everybody,<br><br>first I want to thank everybody involved in the development of gmsh. It is a really great tool and has helped me a lot in my research.<br><br>However I run into a probem when I try to create a 2D quad mesh with the outline of two superimposed disks embedded. However Blossom almost always fails with the message:<br><br>Warning : Perfect Match Failed in Quadrangulation, Applying Graph Splits<br><br>printed 10 times. I attached a simple geometry file that shows this problem.<br><br>For small distances (e.g. dist=2.1) this problem does not occur, but for larger distances (and these are the ones that I want to study), I always get this error.<br><br>For other geometries where I had this problem, playing a bit with the mesh element sizes helped, but I could not find good numbers for this case. I also tried both DelQuad and MeshAdapt as Meshing Algorithms, but I always get the error above.<br><br>I briefly looked at the Blossom Quad publication, but could not find any explanation for this behaviour. My best guess is, that the embedded curve conflicts with a perfect matching, and the extra edges mechanism fails in this case.<br><br>I tested both gmsh 2.6.1 compiled from source and the precompiled gmsh 2.7.0 Linux 64bit binary on Ubuntu 11.10, both show the same behaviour.<br><br>Has anybody an idea how to reformulate the geometry description to avoid this problem?<br><br>Thanks in advance and greetings<br><br>Johannes<br><span><tip.geo></span>_______________________________________________<br>gmsh mailing list<br><a href="mailto:gmsh@geuz.org">gmsh@geuz.org</a><br>http://www.geuz.org/mailman/listinfo/gmsh<br></blockquote></div><br><div apple-content-edited="true">-- <br>Prof. Christophe Geuzaine<br>University of Liege, Electrical Engineering and Computer Science <br><a href="http://www.montefiore.ulg.ac.be/~geuzaine">http://www.montefiore.ulg.ac.be/~geuzaine</a><br><br><br></div><br></div></body></html>