[Gmsh] Problem with extrusion

[Christophe Geuzaine]

Samuel Geniaut wrote:

> Hi,
> 
> When using the option 'layers', it seems that the number you give for the 
> extruded item is only used for the meshed item.
> Therefore, the number of the geometrical item might not be chosen with this 
> option.
> 

Yes, that's the idea--so that one can number the elements in each
layer separately (in order to avoid repeated geometric extrusions).

But Philippe is right: it doesn't work for "Extrude Line" (and "Extrude
Point"). Actually, right now, the layer numbering is only used for
"Extrude Surface"--I will fix this in the next release.

Note that I'm not sure this is the best way to go anyway, since it's
kind of a half baked solution:

- if we use the layer information for the extruded region and its
boundary, it becomes impossible to define useful physical regions on the
boundary (since all the boundary elements get the same region numbers);

- if we use the layer information only for the extruded region (that's
the way I plan to implement it), we won't be able to refer to the
"subdivided" boundaries of extruded regions--only to the one that is
explicitly defined. But since we cannot get the subdivision with the
current implementation either, I guess it's not such a big deal...

Christophe

-- 
Christophe A. Geuzaine
Applied and Computational Mathematics, Caltech
geuzaine at acm.caltech.edu - http://geuz.org