code: def from_region(region, mesh_in, save_edges=False, save_faces=False,
                      localize=False, is_surface=False):
          
          mesh = Mesh( mesh_in.name + "_reg" )
          mesh.coors = mesh_in.coors.copy()
          mesh.ngroups = mesh_in.ngroups.copy()
  
          mesh.conns = []
          mesh.descs = []
          mesh.mat_ids = []
  
          if not is_surface:
              if region.has_cells():
                  for ig in region.igs:
                      mesh.descs.append( mesh_in.descs[ig] )
                      els = region.get_cells( ig )
                      mesh.mat_ids.append( mesh_in.mat_ids[ig][els,:].copy() )
                      mesh.conns.append( mesh_in.conns[ig][els,:].copy() )
  
              if save_edges:
                  ed = region.domain.ed
                  for ig in region.igs:
                      edges = region.get_edges( ig )
                      mesh.descs.append( '1_2' )
                      mesh.mat_ids.append( ed.data[edges,0] + 1 )
                      mesh.conns.append( ed.data[edges,-2:].copy() )
  
              if save_faces:
                  mesh._append_region_faces(region)
  
              if save_edges or save_faces:
                  mesh.descs.append( {2 : '2_3', 3 : '3_4'}[mesh_in.dim] )
                  mesh.mat_ids.append( -nm.ones_like( region.all_vertices ) )
                  mesh.conns.append(make_point_cells(region.all_vertices,
                                                     mesh_in.dim))
  
          else:
              mesh._append_region_faces(region, force_faces=True)
  
          mesh._set_shape_info()
  
          if localize:
              mesh.localize( region.all_vertices )
  
          return mesh
docs: Create a mesh corresponding to a given region.