# [Gmsh] Gmsh: quadrangles and hexahedrons only

zhihua ouyang zxo102 at yahoo.com
Fri Apr 16 11:45:47 CEST 2004

```Dear Gmsh users,
I would like to create meshes consisting of
quadrangles and hexahedrons only. is that possible for
gmsh to do so?
I have tried the following geo file for a while. But
some triangular elements can not be "recombined" into
quadrangles. Can any experienced GMSH users help me
with this? I am using the FEM package from deal.II
which can not handle triangular and  tetrahedral

Ouyang

lc = 10.0;
Point(1) = {0, 0, 0, 9.e-1 * lc};
Point(2) = {200.0, 0,  0, lc} ;
Point(3) = {500.0, 0,  0, lc} ;
Point(4) = {500.0, 200.0, 0, lc} ;
Point(5) = {200.0, 200.0, 0, lc} ;
Point(6) = {100.0, 300.0, 0, lc} ;
Point(7) = {0, 300.0, 0, lc} ;
Point(8) = {0, 200.0, 0, lc} ;

Line(1) = {1,2} ;
Line(2) = {2,5} ;
Line(3) = {5,8} ;
Line(4) = {8,1} ;
Line(5) = {2,3} ;
Line(6) = {3,4} ;
Line(7) = {4,5} ;
Line(8) = {5,6} ;
Line(9) = {6,7} ;
Line(10) = {7,8} ;
Line Loop(11) = {1,2,3,4} ;
Line Loop(12) = {5,6,7,-2} ;
Line Loop(13) = {8,9,10,-3} ;
Plane Surface(14) = {11};
Plane Surface(15) = {12};
Plane Surface(16) = {13};

Transfinite Line{5,6,7,8}=20.001 Using Progression 1;
Transfinite Surface{16} = {5,6,7,8};
Recombine Surface {16} = -360;
Transfinite Line{1,2,5,8}=20.001 Using Progression 1;
Transfinite Surface{14} = {1,2,5,8};
Recombine Surface {14};
Transfinite Line{2,3,4,5}=20.001 Using Progression 1;
Transfinite Surface{15} = {2,3,4,5};
Recombine Surface {15};
MySurface = 100;
Physical Surface(MySurface) = {14,15,16} ;

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