StructuredMesh

Structured Mesh can be obtained in Gmsh by "Transfinite Interpolation" HERE some theoretical background.

Surface Structured Mesh

Structured mesh relay on the command:

• Transfinite Surface { expression-list } | "*" < = { expression-list } > < Left | Right | Alternate > ;

This command relay on the list right hand side expression-list which list the three or the four node defining the mapping to the unitary rectangle. The backing surface shall be a ruled surface or a plane surface satisfying the conditions for a transfinite interpolation.

• Extrude { expression-list } { extrude-list layers }

Actual meshing is performed when the mesh command is issued from the "cli" or from the GUI That's not all it is necessary to issue a "Recombine" command to join triangle in quadrilateral element as in the following snippet of code:

//
//    Define surface
//
Plane Surface(1) = {1};
Transfinite Surface {1} = {1,2,3,4};
Recombine Surface {1};               //  Apply recombination algorithm to 
                                     //   surfaces nedded to have QUAD element

Volume Structured Mesh

As for the surface the volume structured mesh relay on

• Transfinite Surface { expression-list } | "*" < = { expression-list } > < Left | Right | Alternate > ;
• Extrude { expression-list } { extrude-list layers }

The surfaces bounding the volume have to be *transfinite surface* too, see the previous section.

-- RobertoBernetti - 07 Mar 2017