[Gmsh] Elements with negative jacobian after extrusion of a spline

[Paul Cristini]

Thanks a lot, I have no more negative jacobians but unfortunately I am 
facing another problem. I would like to use this with an All Quads mesh 
but when I use this option I have a core dump. If instead of having All 
Quads I have None, it is ok.
Thanks,

Paul
Le 31/01/2013 21:24, Jean-François Remacle a écrit :
> This should be fixed in the highly build
>
> JFR
> Le 31 janv. 2013 à 18:39, Christophe Geuzaine <cgeuzaine at ulg.ac.be 
> <mailto:cgeuzaine at ulg.ac.be>> a écrit :
>
>>
>> Hi Paul,
>>
>> Apparently we broke this (again) in 2.6. (It works fine in 2.5.)
>>
>> We will investigate.
>>
>> Thanks for the report,
>>
>> Christophe
>>
>>
>> On 25 Oct 2012, at 17:44, Paul Cristini <cristini at lma.cnrs-mrs.fr 
>> <mailto:cristini at lma.cnrs-mrs.fr>> wrote:
>>
>>> Hello all,
>>>
>>> I am just trying to do the extrusion of a spline and depending on 
>>> the position of a point of the spline I got 2 elements with a 
>>> negative jacobian.
>>>
>>> Here is the .geo file. If Point(3) = { -L/2,  l+dl/2, 0, lc}; is 
>>> changed to Point(3) = { -L/2,  l+dl/3, 0, lc}; ,which means that one 
>>> point is lowered, then no problem.
>>>
>>> I am generating all quads meshes and  I am also using second order 
>>> elements. I noticed that if I use first order or incomplete second 
>>> order element there is no element with a negative jacobian.
>>>
>>> Any idea of what's going on ?
>>>
>>> Thanks
>>>
>>> Paul
>>>
>>> // Gmsh project created on Sat Apr 10 19:26:34 2010
>>> lambda = 30;
>>> lc=lambda/4;
>>> //
>>> L  = 10 * lambda; // Width
>>> l  =  8 * lambda; // Height
>>> dl =  2 * lambda; // Decalage
>>>
>>> Point(1) = { L, l+dl, 0, lc};
>>> Point(2) = {-L,    l, 0, lc};
>>> //
>>> Point(3) = { -L/2,  l+dl/2, 0, lc};
>>> Point(4) = { 0,  l+dl/3, 0, lc};
>>> Point(5) = { L-L/4,  l+dl/2, 0, lc};
>>>
>>> //lx1 = newl; Line(lx1) = {cx2, cx1};
>>> lx1 = newl; Spline(lx1) = {2, 3, 4, 5, 1};
>>> Extrude {0,1.5*lambda,0} {Line{lx1}; Layers{3};Recombine; };
>>>
>>> -- 
>>> *--------------------------------------------------------------------------*
>>> Paul CRISTINI  Charge de Recherche CNRS / CNRS Research Scientist
>>> --------
>>> CNRS - Laboratoire de Mecanique et d'Acoustique (UPR 7051)
>>>
>>> 31 chemin Joseph Aiguier, F-13402 Marseille Cedex 20 - France
>>> mailto: cristini at lma.cnrs-mrs.fr <mailto:cristini at lma.cnrs-mrs.fr>
>>> phone number: +33 (0)4 91 16 42 89
>>> fax number: +33 (0)4 91 16 44 81
>>> http://www.lma.cnrs-mrs.fr/
>>> *--------------------------------------------------------------------------*
>>>
>>>
>>> _______________________________________________
>>> gmsh mailing list
>>> 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 
>> <http://www.montefiore.ulg.ac.be/%7Egeuzaine>
>>
>>
>>
>
> ------------------------------------------------------------------
> Prof. Jean-Francois Remacle
> Universite catholique de Louvain (UCL)
> Ecole Polytechnique de Louvain (EPL) - Louvain School of Engineering
> Institute of Mechanics, Materials and Civil Engineering (iMMC)
> Center for Systems Engineering and Applied Mechanics (CESAME)
> Tel : +32-10-472352 -- Mobile : +32-473-909930
>
>
>
>
>
>


-- 
*--------------------------------------------------------------------------*
  Paul CRISTINI  Charge de Recherche CNRS / CNRS Research Scientist
  --------
  CNRS - Laboratoire de Mecanique et d'Acoustique (UPR 7051)

  31 chemin Joseph Aiguier, F-13402 Marseille Cedex 20 - France
  mailto: cristini at lma.cnrs-mrs.fr
  phone number: +33 (0)4 91 16 42 89
  fax number: +33 (0)4 91 16 44 81
  http://www.lma.cnrs-mrs.fr/
*--------------------------------------------------------------------------*

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