<html><head></head><body>There is mesh mesh generator called Tetgen (<a class="moz-txt-link-abbreviated" href="http://www.weboo.com/sh/tetgen.htm">www.weboo.com/sh/tetgen.htm</a>)<br>
that uses a tetrahedral quality algorithm.<br>
It seams that it uses the Shewuck's quality algorithm (??)<br>
L. CHAMPANEY<pre>Shewchuk</pre>
<br>
<br>
Jean-Francois Remacle wrote:<br>
<blockquote type="cite" cite="mid:Pine.GSO.4.33.0112070821100.14927-100000@jumpgate.scorec.rpi.edu">
<blockquote type="cite"><pre wrap="">Hello,<br></pre></blockquote>
<pre wrap=""><!----><br>Hello,<br><br></pre>
<blockquote type="cite"><pre wrap="">I've been trying to use gmsh to construct 3D tetrahedral grids for our<br>CFD work. I have run into considerable problems due to the creation of<br>very flat tetrahedra when producing grids for complex geometries. Most<br>of the<br>flat tetrahedra are rather envelope-shaped. If you are interested, I<br>can send a .geo file which will produce this effect.<br></pre></blockquote>
<pre wrap=""><!----><br>The current version of the 3D tet mesh generator does not involve<br>any optimization steps. That means that slivers are often generated.<br>We have a procedure to improve mesh quality by edge and<br>face swapping but I just looked into the code and that part<br>is commented ;-) I guess there are bugs.<br><br></pre>
<blockquote type="cite"><pre wrap="">This mucks up my calculations due to instabilities.<br><br></pre></blockquote>
<pre wrap=""><!----><br>Yes, I know.<br><br></pre>
<blockquote type="cite"><pre wrap="">I'm aware that the 3D grid generator is still experimental, but<br>nevertheless I would like to ask if there exists a sort of<br>workaround for this. Or is it foreseen that the problem will<br>be tackled in the near future?<br></pre></blockquote>
<pre wrap=""><!----><br>If you can find a tet mesh optimizator, that would help. I'm<br>going to work on that part and see what is wrong in my optimization<br>procedure.<br><br></pre>
<blockquote type="cite"><pre wrap="">Otherwise I must say that the software looks very nice. I actually<br>used it for a number of grids, but most of them have proven to be not<br>really that useful due to this problem :-(.<br></pre></blockquote>
<pre wrap=""><!----><br>Too bad, we're going to work on that.<br><br>JF<br><br></pre>
<blockquote type="cite"><pre wrap="">TIA for any answer<br><br>Thomas<br><br><br></pre></blockquote>
<pre wrap=""><!----><br>_______________________________________________<br>Gmsh mailing list<br><a class="moz-txt-link-abbreviated" href="mailto:Gmsh@geuz.org">Gmsh@geuz.org</a><br><a class="moz-txt-link-freetext" href="http://www.geuz.org/mailman/listinfo/gmsh">http://www.geuz.org/mailman/listinfo/gmsh</a><br><br><br><br></pre>
</blockquote>
<br>
</body></html>