[Gmsh] Regular-triangle mesh generation problem

[Christophe Geuzaine]

Daniel Vieira Soares wrote:
> Hi,
> 
> I am facing a problem when I try to create structured triangle meshes. I 
> want to produce a triangular mesh whose elements are defined by parallel 
> lines, or better, with lines that connect respective pairs from the 
> boundary - figure triang01.jpg attached shows that.
> 
> When I create a transfinite triangular mesh with 16 elements (17 nodes) 
> per boundary, I usually get the elements of the mesh defined by 
> baselines that describe some sort of an arc around the first boundary 
> point given to the algorithm (shown in figure triang02.jpg attached is 
> an example, when the right angle node is the first point given to the 
> transfinite surface algorithm).
> 
> The mesh in triang01.jpg is created by defining all transfinite lines 
> with 2 nodes, and then refining over and over. This obviously restrict 
> my meshing options (and isn't desirable), because this way I cannot 
> define a progression which the elements of some chosen boundary must obey.
> 
> I don't really like the mesh created in the normal way (triang02.jpg) 
> because the elements around the "center" point (in this case, the right 
> angle node) are too narrow, or in another way, are too degenerated when 
> compared to other elements, and my simulation program is (too much) 
> badly affected by this.
> 
> Can someone help me with this???


You would need to define another rule for generating the nodes and the
elements... It cannot be handled by the "transfinite" algorithm because 
it would destroy the compatibility with the 3-D case.

A good starting point might be the code in Mesh/meshGFaceTransfinite.cpp.


> 
> Cheers,
> 
> Daniel
> 
> P.S. If there is any problem in accessing the images, I can put them 
> online in my webhost.
> 
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-- 
Prof. Christophe Geuzaine
University of Liege, Electrical Engineering and Computer Science
http://www.montefiore.ulg.ac.be/~geuzaine