:*In LoD2 a solid contains external references (Xlinks) to the real bounding geometry. '''Surfaces, which do not exist in reality''' are modeled as closure surfaces and assigned directly to the building part ('''Figure C'''). | :*In LoD2 a solid contains external references (Xlinks) to the real bounding geometry. '''Surfaces, which do not exist in reality''' are modeled as closure surfaces and assigned directly to the building part ('''Figure C'''). |