[Gmsh] characteristic length; algorithms
Christophe Geuzaine
cgeuzaine at ulg.ac.be
Wed Jan 30 08:33:21 CET 2008
Constanze Bausch wrote:
> Christoph,
>
>
>
> thanks for your reply. When I change the characteristic length factor
> for example to 0.5, I do understand, that the mesh size is going to be a
> half smaller.
>
> But how comes off the first mesh size, which is used? How is
> characteristic length defined?
>
When no characteristic length is given (e.g. with step files), Gmsh uses
the size of the object divided by 10. Once you set at least one char.
length (on a geometry point, using a background mesh, etc.), then this
default is ignored.
>
>
> I’m doing some evaluation and describing of mesh generation tools for my
> diploma thesis. Therefore I also describe meshing algorithms that are used.
>
> In your tool “Delaunay” for surface meshing is still experimental, as
> you say. I would like to know, which algorithm is meant by “MeshAdapt”.
> Maybe you can recommend an article about it?
This algorithm implements an original surface meshing strategy based on
the concept of local mesh modifications, which hasn't been published yet.
>
> And I noticed that every new mesh has a different structure, even though
> the same parameters are used. Is the reason based on an algorithm, which
> creates new points by coincidence?
Yes, the algorithm is randomized.
>
>
>
> Thank you very much for your effort!
>
> Constanze
>
>
>
>
>
>
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>
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--
Prof. Christophe Geuzaine
University of Liege, Electrical Engineering and Computer Science
http://www.montefiore.ulg.ac.be/~geuzaine