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<p class="MsoNormal"><span lang="NL-BE">Dear all,<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="NL-BE"><o:p> </o:p></span></p>
<p class="MsoNormal">I’m trying to get access to the full geometry of a certain model created using gmsh. For example, consider the following *.geo file:
<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Point(1)={0, 0, 0}; <o:p></o:p></p>
<p class="MsoNormal">Point(2)={1, 0, 0};<o:p></o:p></p>
<p class="MsoNormal">Point(3)={0, 1, 0}; <o:p></o:p></p>
<p class="MsoNormal">Circle(1)={2,1,3}; <o:p></o:p></p>
<p class="MsoNormal">Line(2)={2,3};<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">This *.geo file creates a quarter circle and a straight line. When using the Mesh.SaveTopology option, all entities are saved in the $Entities … $EndEntities section:<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">$Entities<o:p></o:p></p>
<p class="MsoNormal">3 2 0 0<o:p></o:p></p>
<p class="MsoNormal">1 0 // Point 1<o:p></o:p></p>
<p class="MsoNormal">2 0 // Point 2<o:p></o:p></p>
<p class="MsoNormal">3 0 // Point 3<o:p></o:p></p>
<p class="MsoNormal">1 2 2 3 0 // Line 1 (=circle)<o:p></o:p></p>
<p class="MsoNormal">2 2 2 3 0 // Line 2<o:p></o:p></p>
<p class="MsoNormal">$EndEntities <o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">As you can see, lines 1 and 2 seem to be identical entities, while in reality they are not. Line 1 is a quarter circle, while line 2 is a straight line. Is there a way to export the full geometry/topology information from gmsh at the moment?
Thus, for a circle, this would be three points (the input points provided to the Circle command). My goal is to use gmsh as a mesh generator and couple it to an existing MATLAB finite element solver. Extracting the precise topology from gmsh allows for the
easy definition of boundary conditions (e.g. distributed load on a circular line segment or pressure on a curved surface).
<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thanks in advance. <o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Kind regards,<o:p></o:p></p>
<p class="MsoNormal">Pieter Reumers<o:p></o:p></p>
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