3D Cadastres 3D Data Models 3D SPATIAL RELATIONSHIPS MODEL: A USEFUL CONCEPT FOR 3D CADASTRE?

This paper contains some reflections about using 3D topology, and more generally some 3D concepts related to 3D cadastre. Firstly, we develop some conceptual views about 3D modelling and more specifically about the definition of 3D spatial objects. Secondly, we present a new framework for representing spatial relationships. The framework has different “complexity” levels and allows mixing simple and complex spatial relationships. Therefore, it is possible to consider different levels when querying spatial objects. Finally, some examples are presented in R that demonstrate the applicability of the framework for cadastral objects. INTRODUCTION THE EVOLUTION TO 3D For many years, acquisition techniques and computational processes evolve continually and the practical limitations of the use of 3D information decrease. But in most of the cases and especially in urban contexts, the evolution to real 3D geo-objects is rather slow. This could be explained by a strong inhibitor factor, i.e. the inheritance of 2D way of thinking. The primary reflex when upgrading a 2D model, for example the cadastral model, may be to keep the 2D object’s definition and add some 3D extensions. Even if the result is satisfactory, the approach is incomplete and limitative. The opportunity of working with 3D data allows us to consider the 3D world where many objects can significantly evolve. If an object has a