[Gmsh] 2d elements appear at 3d meshing

David Colignon David.Colignon at ulg.ac.be
Fri May 25 12:37:14 CEST 2007

Hi Alexander,

in your .geo file, you didn't define any Physical entity, so ALL mesh elements are saved, including line segments, surface triangles, etc. as explained in


If you want to only save tetrahedra, just add 

Physical Volume (999) = {109,111,113,115} ; 

at the end of your .geo file



Alexander Rabtchevich wrote:
> Hello, Dave
> Here is the mesh, obtained with the settings you'd described. Gmsh 2.0.7 
> under Windows.
> If you look through the elements from the beginning you will find there 
> are some very strange ones. At least I do not understand 2 points elements.
> Sorry for a big file.
> David Colignon wrote:
>> Hi Alexander,
>> with Netgen, only 1 smothing step and tetrahedra quality optimization 
>> turned on, I got a rather nice looking mesh, so I don't understand 
>> your problem.
>> Can you send me the mesh you obtain ?
>> Cheers,
>> Dave
>> Alexander Rabtchevich wrote:
>>> I've got the same problem as before - in order to decrease the number 
>>> of elements I use big characteristic length. And when the program 
>>> produces 3d meshing, it makes even segments, not only triangles 
>>> instead of all tetrahedrals. The 3d algorithm is Netgen, number of 
>>> smoothing steps is 15, tetrahedra quality optimization is turned on.
>>> Is there a solution to the problem described?