[Gmsh] Gmsh 2.0 quad recombine

Christophe Geuzaine cgeuzaine at ulg.ac.be
Thu Jul 19 12:38:00 CEST 2007


Lutz Nietner wrote:
> Dear all,
> 
> I've been using Gmsh 1.65 for generating 2D-quads in my own code, basing on
> snippets like that:
> 
> Mesh.Algorithm = 2;
> Mesh.RecombineAlgo = 2;
> Point(1) = {0,0,0,0.1};
> Point(2) = {0,2,0,0.1};
> Point(3) = {0,1.93185165257814,-0.517638090205042,0.1};
> Point(4) = {0,1.73205080756888,-1,0.1};
> Point(5) = {0,1.4142135623731,-1.41421356237309,0.1};
> Point(6) = {0,1,-1.73205080756888,0.1};
> Point(7) = {0,0.517638090205041,-1.93185165257814,0.1};
> Point(8) = {0,1.22460635382238E-16,-2,0.1};
> Line(1) = {1,2};
> Line(2) = {2,3};
> Line(3) = {3,4};
> Line(4) = {4,5};
> Line(5) = {5,6};
> Line(6) = {6,7};
> Line(7) = {7,8};
> Line(8) = {8,1};
> Line Loop(9) = {1,2,3,4,5,6,7,8};
> Plane Surface(10) = {9};
> Recombine Surface {10};
> 
> In release 1.65, the code above produces always a good unstructured quad
> pattern. In release 2, the recombine algorithm sometimes leaves triangles.
> What's the reason for?
> 

We haven't yet recoded "Mesh.RecombineAlgo = 2" (full quad recombine) in 
the Gmsh 2.0.x series. It should be back in Gmsh 2.1.x.



> Best regards
> 
> Lutz Nietner
> 
> 
> _______________________________________________
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> gmsh at geuz.org
> 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