I have some problem with the definition of normal when the mesh is imported from gmsh.
Indeed, taking a 2d mesh of gmsh (on my .msh file I have a component in z but which is worth 0 everywhere) and defining a normal like n = FacetNormal (mesh), I get len(n) = 3.
So I have the n_z component in addition.
For some other software, I have directly a normal of length 2.
Is it normal ? If not, what is the way to automatically obtain a normal of length 2 (without having to extract the first two components of the 3-dimensional one) ?