Zenker, Dr. Matthias wrote: > Hi, > > (just returned from holidays...) > thank you for the hint with the fields, I will try it that way. > I have examined demos/fields.geo. Seems like I have to enter all that > field-related stuff by hand. I don't mind to do so, but is there a more > elegant way, using the GUI? And can I visualize the defined fields > before starting the meshing?
Yes: download the latest nightly snapshot, and in the Mesh module click on "Define", then "Fields". > > Best regards, > > Matthias > >> -----Original Message----- >> From: Christophe Geuzaine [mailto:[email protected]] >> Sent: Tuesday, December 16, 2008 9:41 AM >> To: Zenker, Dr. Matthias >> Cc: [email protected] >> Subject: Re: [Gmsh] lower limit for characteristic length >> >> Zenker, Dr. Matthias wrote: >>> Of course. Here it is. >>> >>> BTW, I use gmsh 2.2.6 on a WIN XP SP 2, Pentium 4, 3.2 GHz, >> 1.5 GB RAM >>> computer. >>> >> The default random perturbation factor seems to be a bit >> small in your case. The following (increased "-rand" from >> "1.e-9" to "1.e-7") >> >> gmsh small_cl.geo -2 -rand 1.e-7 >> >> seems to work just fine, but I had to stop it before the end >> due to insufficient memory on my laptop. Multiplying all the >> element sizes by 3 and using the faster del2d algorithm >> >> gmsh small_cl.geo -2 -rand 1.e-7 -clscale 3 -algo del2d >> >> produced a nice mesh with about 23 million triangles. >> >> >>> If I could force gmsh not to ignore the cl of the spline control >>> points, it would probably be faster for such a case (if it wouldn't >>> crash). Is there a trick to do that? Would it help to put isolated >>> points with the desired cl at the desired location? >> You should probably use Fields to fine-tune the element >> sizes. There are some examples on the mailing list, as well >> as in demos/fields.geo. >> >> >> >>> Thank you and best regards, >>> >>> Matthias >>> >>>> -----Original Message----- >>>> From: Christophe Geuzaine [mailto:[email protected]] >>>> Sent: Monday, December 15, 2008 1:07 PM >>>> To: Zenker, Dr. Matthias >>>> Cc: [email protected] >>>> Subject: Re: [Gmsh] lower limit for characteristic length >>>> >>>> Zenker, Dr. Matthias wrote: >>>>> Hi there, >>>>> >>>>> the question remains: is there a lower limit for the >> characteristic >>>>> length cl, and why does gmsh crash when some points have >> a small cl? >>>> It shouldn't crash, except when "cl" divided by the overall >>>> size of model is getting close to machine accuracy (or more >>>> accurately, close to the value of the random pertutbation >>>> used in the meshing algorithms, which is 1e-9 by default). >>>> >>>> Could you send a file that shows the problem? >>>> >>>> >>>>> I would like to add another one: Is it possible that gmsh >>>> ignores the >>>>> cl of the control points of a spline except for the first >> and last >>>>> one? If >>>> That's what Gmsh does: the cls of the control points are ignored. >>>> >>>> >>>> >>>>> so, is there a way to force gmsh to take into account the >> cl of the >>>>> intermediate points also? >>>>> >>>>> Best regards, >>>>> >>>>> Matthias >>>>> >>>>> >>>> -------------------------------------------------------------- >>>> ---------- >>>>> *From:* [email protected] >> [mailto:[email protected]] *On >>>>> Behalf Of *Zenker, Dr. Matthias >>>>> *Sent:* Monday, November 17, 2008 10:49 AM >>>>> *To:* [email protected] >>>>> *Subject:* Re: [Gmsh] lower limit for characteristic length >>>>> >>>>> I was wrong, it crashes also for cl=0.0005 (but after a >>>> looong time, >>>>> and with a runtime error). >>>>> >>>>> >>>> -------------------------------------------------------------- >>>> ---------- >>>>> *From:* [email protected] >>>> [mailto:[email protected]] *On >>>>> Behalf Of *Zenker, Dr. Matthias >>>>> *Sent:* Monday, November 17, 2008 10:16 AM >>>>> *To:* [email protected] >>>>> *Subject:* [Gmsh] lower limit for characteristic length >>>>> >>>>> Hi, >>>>> >>>>> I wonder if there is a lower limit for the characteristic >>>>> length. I have a rather simple 2D geometry, and if >>>> I set the cl >>>>> for just two points to 0.0001, gmsh crashes during >>>> the meshing >>>>> after having given the error message "3 identical >> points in >>>>> Qtest". The .gmsh-errors file is not written. With >>>> cl=0.0005, >>>>> this does not happen (but it takes veeery long to >>>> compute the mesh). >>>>> Best regards, >>>>> >>>>> Matthias >>>>> >>>>> >>>> ---------------------------------------------------------------- >>>>> ERBE Elektromedizin GmbH >>>>> Dr.rer.nat. Matthias Zenker >>>>> Dipl. Phys. >>>>> Grundlagenentwicklung Technologie >>>>> Waldhoernlestrasse 17 >>>>> D-72072 Tuebingen >>>>> Tel.: + 49 (0) 7071 - 755 226 >>>>> Fax: + 49 (0) 7071 - 755 5226 >>>>> E-Mail: <_mailto:[email protected]_> >>>>> URL: _http://www.ERBE-med.de_ >>>>> >>>>> ---------------------------------------------------------------- >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> ERBE Elektromedizin GmbH >>>>> Firmensitz: 72072 Tuebingen >>>>> Geschaeftsfuehrer: Christian O. Erbe, Reiner Thede >>>>> Registergericht: Stuttgart HRB 380137 >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> ERBE Elektromedizin GmbH >>>>> Firmensitz: 72072 Tuebingen >>>>> Geschaeftsfuehrer: Christian O. Erbe, Reiner Thede >>>>> Registergericht: Stuttgart HRB 380137 >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> ERBE Elektromedizin GmbH >>>>> Firmensitz: 72072 Tuebingen >>>>> Geschaeftsfuehrer: Christian O. Erbe, Reiner Thede >>>>> Registergericht: Stuttgart HRB 380137 >>>>> >>>>> >>>>> >>>>> >> ---------------------------------------------------------------------- >>>>> -- >>>>> >>>>> _______________________________________________ >>>>> 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 >>>> >>> >> _____________________________________________________________________ >>> ERBE Elektromedizin GmbH >>> Firmensitz: 72072 Tuebingen >>> Geschaeftsfuehrer: Christian O. Erbe, Reiner Thede >>> Registergericht: Stuttgart HRB 380137 >>> >>> >>> >>> >> -------------------------------------------------------------- >> ---------- >>> _______________________________________________ >>> 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 >> >> >> > > _____________________________________________________________________ > ERBE Elektromedizin GmbH > Firmensitz: 72072 Tuebingen > Geschaeftsfuehrer: Christian O. Erbe, Reiner Thede > Registergericht: Stuttgart HRB 380137 > > > _______________________________________________ > 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
