<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><br class=""><br class=""><blockquote type="cite" class="">On 24 Apr 2020, at 09:21, Christophe Geuzaine <<a href="mailto:cgeuzaine@uliege.be" class="">cgeuzaine@uliege.be</a>> wrote:<br class=""><br class=""><br class="">Hi Lars,<br class=""><br class="">The default algorithm (Frontal-Delaunay) sometimes still has trouble with size fields with small features. You might want to use the Delaunay algorithm in such cases:<br class=""><br class="">Mesh.Algorithm = 5;<br class=""><br class="">(I will add a note in the documentation about this.)<br class=""><br class="">For 3D meshes, the latest development snapshot includes mesh size field support in the new 3D algorithm HXT (Mesh.Algorithm3D = 10). Your feedback on this experimental support will be very welcome!<br class=""><br class=""></blockquote><div class=""><br class=""></div><div class="">At first sight it seems ok:</div><div class=""><br class=""></div><div class=""><img apple-inline="yes" id="7F781DD5-7B51-4E60-A78A-4E5F67289922" width="1308" height="926.5" src="cid:52DB4D47-5CAA-4541-9A56-09714A8AEB2E@home" class=""></div><br class=""><blockquote type="cite" class="">Cheers,<br class=""><br class="">Christophe<br class=""><br class=""><br class=""><blockquote type="cite" class="">On 23 Apr 2020, at 17:54, Lars Hubatsch <<a href="mailto:hubatsch@pks.mpg.de" class="">hubatsch@pks.mpg.de</a>> wrote:<br class=""><br class="">Hi all,<br class=""><br class="">I’m trying to create a disk mesh with a given background and, within a rim around the center, a local decrease of the characteristic length that follows a Gaussian (see attached image 1).<br class=""><br class="">Code:<br class=""><br class="">SetFactory("OpenCASCADE");<br class="">Disk(1) = {0, 0, 0, 4};<br class="">Physical Surface("surfacedomain") = {1};<br class=""><br class="">Field[3] = MathEval;<br class="">Field[3].F = ".5 - (.5-0.01)*exp(-(1./0.1) *((sqrt(x*x+y*y)-1))*((sqrt(x*x+y*y)-1)))";<br class=""><br class="">Background Field = 3;<br class=""><br class="">However, for the parameters above the rim is not closed, what am I getting wrong?<br class="">If I change parameters slightly, e.g. 0.1 to 0.2 or 0.01 to 0.005 I get the correct representation. My problem is, that I eventually would like to do this in 3D within a sphere instead of a disk. However, this is visually harder to inspect (or is there a good way to do this?), so I would like to make sure that things work in principle in 2D.<br class=""><br class="">Thanks,<br class="">Lars<br class=""><br class=""><Screenshot 2020-04-23 at 17.54.29.png><br class="">_______________________________________________<br class="">gmsh mailing list<br class=""><a href="mailto:gmsh@onelab.info" class="">gmsh@onelab.info</a><br class="">http://onelab.info/mailman/listinfo/gmsh<br class=""></blockquote><br class="">— <br class="">Prof. Christophe Geuzaine<br class="">University of Liege, Electrical Engineering and Computer Science <br class=""><a href="http://www.montefiore.ulg.ac.be/~geuzaine" class="">http://www.montefiore.ulg.ac.be/~geuzaine</a><br class=""><br class=""><br class=""><br class=""></blockquote><br class=""><div class="">— <br class="">Prof. Christophe Geuzaine<br class="">University of Liege, Electrical Engineering and Computer Science <br class=""><a href="http://www.montefiore.ulg.ac.be/~geuzaine" class="">http://www.montefiore.ulg.ac.be/~geuzaine</a><br class=""><br class=""><br class=""></div><br class=""></body></html>