Empty physical groups vector when loading from .msh file with physical groups [C++ API]
Opening a mesh (v2.2) file with physical names defined and asking for physical groups results in an empty vector.
gmsh::initialize();
gmsh::open("something.msh");
gmsh::vector_pair physGroups;
gmsh::model::getPhysicalGroups(physGroups); //returns empty vector
However, later, we can get a list of all the entities in the mesh:
gmsh::vector_pair allEntities;
gmsh::model::getEntities(allEntities);
However, calls to getPhysicalName(dim, tag, physName)
for the entity values can return an actual physical name.