3D CITY MODEL AS A FIRST STEP TOWARDS DIGITAL TWIN OF SOFIA CITY

Abstract. Semantic 3D city models are increasingly applied for a wide range of analysis and simulations large urban areas. Such used as foundation development digital twins, representing with high accuracy the landscapes areas well dynamic in terms processes events. In this context, paper presents model, which is starting point twin Sofia city. The model compliant CityGML 2.0 LOD1, supporting integration buildings terrain enriching buildings’ attributes address information. District Lozenets chosen pilot area modelling. An approach transformation proprietary geospatial data into schemas presented. an essential part it, since often partially float over or sink terrain. A web application user interaction developed. Its main features include silhouetting single building, showing relevant overlay content, displaying shadows styling depending on their attributes.