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<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt; font-family:"Calibri","sans-serif"; color:#1F497D">Hi Christophe,</span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt; font-family:"Calibri","sans-serif"; color:#1F497D"> </span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt; font-family:"Calibri","sans-serif"; color:#1F497D">thank you for the quick reply!</span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt; font-family:"Calibri","sans-serif"; color:#1F497D">I have continued to experiment on my side. It seems that mmg3d can cope with internal surfaces if the mesh is not too fine. If I use h2/20 in
my example (with the interface), gmsh doesn’t crash. It also seems that a larger absolute mesh width does not improve things: If I multiply all lengths by 10, I still get the crash, even with h2/20. BTW gmsh takes more time to do the 2D mesh with all lengths
multiplied by 10 even though the number of triangles should be almost unchanged.</span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt; font-family:"Calibri","sans-serif"; color:#1F497D">Could it be that the sudden change in mesh width in z direction is a cause of the problem? I might change my field definitions in order to have
a more gradual change of mesh width – do you think this would help?</span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt; font-family:"Calibri","sans-serif"; color:#1F497D"> </span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt; font-family:"Calibri","sans-serif"; color:#1F497D">Matthias</span></p>
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<p class="MsoNormal"><b><span style="font-size:10.0pt; font-family:"Tahoma","sans-serif"">Von:</span></b><span style="font-size:10.0pt; font-family:"Tahoma","sans-serif""> Christophe Geuzaine [mailto:cgeuzaine@ulg.ac.be]
<br>
<b>Gesendet:</b> Donnerstag, 11. Juli 2013 22:58<br>
<b>An:</b> Zenker, Dr. Matthias<br>
<b>Cc:</b> gmsh@geuz.org Geuzaine; Jean François Remacle<br>
<b>Betreff:</b> Re: crash on 3D meshing (AW: Anisiotropic mesh in stacked layers)</span></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt"><span style="font-size:10.0pt"><br>
Hi Matthias,<br>
<br>
There are two separate problems:<br>
<br>
1) Currently MMG3D does not like having internal surfaces in the volume. Attached is a file with a single volume, which works ok.<br>
<br>
@JF : have you tried MMG3D in such cases with internal surfaces?<br>
<br>
2) "h2 / 100" pushes the initial tetrahedralization to the limit; h2/90 works fine over here.<br>
<br>
All of this is still very experimental, though. It all needs to be tested and documented.<br>
<br>
Thanks for the feedback!<br>
<br>
Christophe</span></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt"><span style="font-size:10.0pt"><br>
<br>
</span><span lang="EN-US" style="font-size:10.0pt">On 11 Jul 2013, at 17:29, "Zenker, Dr. Matthias" <</span><span style="font-size:10.0pt"><a href="mailto:Matthias.Zenker@erbe-med.com"><span lang="EN-US">Matthias.Zenker@erbe-med.com</span></a></span><span lang="EN-US" style="font-size:10.0pt">>
wrote:<br>
<br>
> I forgot to say that the crash happens under Windows 7 with gmsh 2.8.0 64bit and with 2.7.1 32bit and 64bit.<br>
</span><span style="font-size:10.0pt">> <br>
> Matthias<br>
> <br>
> _____________________________________________<br>
> Von: Zenker, Dr. Matthias <br>
> Gesendet: Donnerstag, 11. </span><span lang="EN-US" style="font-size:10.0pt">Juli 2013 16:57<br>
> An: 'gmsh@geuz.org'<br>
> Cc: 'Christophe Geuzaine [cgeuzaine@ulg.ac.be] (</span><span style="font-size:10.0pt"><a href="mailto:cgeuzaine@ulg.ac.be"><span lang="EN-US">cgeuzaine@ulg.ac.be</span></a></span><span lang="EN-US" style="font-size:10.0pt">)'<br>
> Betreff: crash on 3D meshing (AW: Anisiotropic mesh in stacked layers)<br>
> <br>
> <br>
> Hi,<br>
> <br>
> now that I have successfully created a anisotropic mesh width field for my geometry, I get a crash when I do the 3D meshing.
</span><span style="font-size:10.0pt">2D meshing works without problem. I have the impression that the desired mesh width may be too small. Is this so, and what is the smallest mesh width gmsh can cope with?<br>
> <br>
> Thanks for an answer, this time…<br>
> <br>
> Matthias<br>
> <br>
> < Datei: layers.geo >><br>
> _____________________________________________<br>
> Von: Zenker, Dr. Matthias <br>
> Gesendet: Donnerstag, 11. </span><span lang="EN-US" style="font-size:10.0pt">Juli 2013 16:41<br>
> An: 'gmsh@geuz.org'<br>
> Cc: 'Christophe Geuzaine [cgeuzaine@ulg.ac.be] (</span><span style="font-size:10.0pt"><a href="mailto:cgeuzaine@ulg.ac.be"><span lang="EN-US">cgeuzaine@ulg.ac.be</span></a></span><span lang="EN-US" style="font-size:10.0pt">)'<br>
> Betreff: AW: Anisiotropic mesh in stacked layers<br>
> <br>
> <br>
> Hi again,<br>
> <br>
> I have got it to work, but I still don’t understand why. </span><span style="font-size:10.0pt">It seems that the fields in MathEvalAniso have to be 1/(mesh_width)^2. But why?<br>
> I have read the relevant part of the gmsh manual, but didn’t find the answer there.<br>
> A short explanation and/or a pointer to more info would be highly appreciated.<br>
> <br>
> Matthias<br>
> <br>
> _____________________________________________<br>
> Von: Zenker, Dr. Matthias <br>
> Gesendet: Mittwoch, 10. </span><span lang="EN-US" style="font-size:10.0pt">Juli 2013 17:09<br>
> An: </span><span style="font-size:10.0pt"><a href="mailto:gmsh@geuz.org"><span lang="EN-US">gmsh@geuz.org</span></a></span><span lang="EN-US" style="font-size:10.0pt"><br>
> Cc: Christophe Geuzaine [cgeuzaine@ulg.ac.be] (</span><span style="font-size:10.0pt"><a href="mailto:cgeuzaine@ulg.ac.be"><span lang="EN-US">cgeuzaine@ulg.ac.be</span></a></span><span lang="EN-US" style="font-size:10.0pt">)<br>
> Betreff: Anisiotropic mesh in stacked layers<br>
> <br>
> <br>
> Hi,<br>
> <br>
> I want to mesh a geometry with layers stacked in z direction, where each layer should have a mesh width in the xy plane, and a different one in z direction.
</span><span style="font-size:10.0pt">I have tried to combine the Box, Min and MathEval Aniso fields to achieve this (see attachment). But the mesh widths are not as I expect, in particular in layer 2 in z direction it should be 1/20 its height. What do I do
wrong?<br>
> How is the mesh width derived from the m11, m22 and m33 fields in MathEvalAniso?<br>
> <br>
> Thanks for some explanations and hints,<br>
> <br>
> Matthias<br>
> <br>
> < Datei: layers.geo >><br>
> <br>
> <br>
> <br>
> _____________________________________________________________________<br>
> ERBE Elektromedizin GmbH<br>
> Firmensitz: 72072 Tuebingen<br>
> Geschaeftsfuehrer: Christian O. Erbe, Reiner Thede<br>
> Registergericht: Stuttgart HRB 380137<br>
> <br>
> <layers.geo><br>
<br>
-- <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>
</span></p>
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Firmensitz: 72072 Tuebingen<br>
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