Integrating Dynamic Data with 3D City Models via CityJSON Extension

Semantic 3D city models have been widely used to solve problems that affect the human-built environment. Due to the complexity of the city and its dynamic aspect, these models should allow studying the evolution of a phenomena in real time. Therefore, 3D city models are evolving towards Digital Twin of cities to allow handling the dynamic aspect of the city. For instance, such evolution requires real-time data to be collected using Internet of Things devices (IoT). This kind of dynamic data requires specific tools that should allow its particular exploitation and manipulation. To model the urban environment, CityGML and CityJSON for instance, as international 3D standards, allow creating, storing and exchanging 3D city models in an interoperable way. This paper aims to propose and implement a methodology for integrating real-time data in a city model by using the “Dynamizer” extension of CityGML based on CityJSON. We then have developed a web interface plugin to handle IoT data and their interactive visualization as a first step for future simulations. This solution allows the understanding of the 3D city model encoded with JSON, also the simplification and the easy comprehension of the Dynamizer extension compared to the CityGML solution which is difficult to decipher. The solution also makes it possible to establish the connection between the physical entities and their digital twins, to follow the evolution of their real characteristics over time, to represent them, analyze them and take the appropriate decision to preserve the components of the territory, to manage it correctly and ensure its resilience and sustainability.