[Gmsh] Physical Surface of a part of a surface

[Geordie McBain]

2013/11/25 Lakshmi Selvakumaran <lakshmi.selvakumaran at kaust.edu.sa>:
> Hi,
>
> I  have a 3D mesh and want to assign part of the surface to a physical
> surface with a specific label.  But it seems that I have to modify the whole
> geometry to include this surface and it looks like I have to redo the whole
> geometry again.  Is it possible to assign a part of a surface as a physical
> mesh without having to create this subsurface explicitly and re-meshing
> everything around it?

Does the 'Reclassify 2D' tool do what you want?  It's not really
documented in the manual (though it is mentioned at
http://geuz.org/gmsh/doc/texinfo/gmsh.html#t13_002egeo), but it can be
found in the GUI under Mesh.