Digital Open Urban Twin

3D City Model

The 3D city model-Digital Twin project works on the development of studies concerning digital urban models of the DOUT – Digital Open Urban Twin project (2018-2019). The purpose, in the outline of DOUT, is to study the integrated methodological approach for the generation of an open data platform to collect, integrate, manage data and information on an urban scale and to simulate the actions and effects of policies on cities. The preliminary phase of the research involved the exploration of BIM-GIS-oriented urban-scale data modeling platforms and their adaptability and compliance with principles of standards and interoperability (Eg: 3DS-Dassault Systèmes 3D experience). The project also operates in the direction of implement a methodological approach and technological process towards the structure of a spatial database starting from the case of the City of Turin. This 3D city model is intended as an innovative concept of Digital Twin, that is the digital replica of the city, not only capable of reproducing the existing physical condition, but also integrating morphological and semantic aspects, and, in the future, able to implement forecasting algorithms capable to formulating hypotheses on the effects of urban dynamics and policies.




#Urbanism #DigitalTechnologies&DataScience


Research project

In the framework of urban studies for the analysis of phenomena and transformation processes of the today city, aimed at the planning and the design purposes, the multidisciplinary approach is a great challenge. The possibility to benefit from a 3D enriched representation of reality, beyond the traditional 2D maps point of view, provides an advanced spatial analysis at urban scale for the study of the socio-economic phenomena that drives urban regeneration.

In order to analyse and monitor these dynamics, it is essential to have geo-spatial tools that manage geographic data, in the form of numerical cartography and 3D models, allowing the identification and quantification of urban transformations and any area that needs further urban regeneration interventions, in order to implement localized actions, preserving the built heritage of the city. For this reason, acquisition tools, measurements techniques and multi-source and multi-content products derived from Geomatics approaches are a valuable support for the analysis and modelling of the urban legacy and built space and human phenomena too that constitute the city. 

The Geomatics research applied to the city modelling is going to investigate, in the last 10 years, on the issues related to the concept of 3D city models. The current perspective of this research interest is the possibility to model not only 3D and semantic information of urban objects but also multi-dimensional information, especially related to past time resolution, in order to simulate future behaviour. In fact, recent years, 3D city model and Digital Twin concepts have become increasingly relevant, not only in the Geomatics field, but also in various fields of research such as urban planning, urban regeneration activities in the field of cultural heritage and then in the monitoring of transformation processes of the city. Currently, a research key is still far from being solved and it is represented by the integration of standards, formats and modelling techniques adopted by GIS territorial analysis systems (focused in the production of territorial numerical maps) and BIM and HBIM database (fundamental for a 3D relational parametric modelling at architectural scale). Therefore, it will be fundamental to manage and adopt different data sources within platforms able to manage and test their flexibility towards a possible integration within a unique relational, structured and multi-content/multi-scale geo-database. 

The topics that the research project 3D city model-digital twin is going to progressively face, in an interdisciplinary analysis perspective related to 3D city models conception and structuring, are: the geometric problem, the semantic problem, the relations problem, the thematic content problem.

From these assumptions, starting from the analysis of standards (preferably with open-source approach), structured geospatial data, tools and methodologies available today, the project is focusing on the definition of an urban modelling code, for design and planning tool able to support local decision-making processes, in the form of 3D geo-database (.gdb) suitable for hosting complex and interconnected thematic data (about built heritage, energy consumption, acoustics studies, traffic analysis, floor information, etc.). This is conducted with particular consideration on a possible definition, through the support of geo-processing operations, of a model able to detect and identify the different levels of each building entity (derived from structured cartography of Spatial Data infrastructure implemented and updated).

Therefore, the research’s objective is the development of a structured geometrically and semantically 3D City Model, related to the Torino municipality, on the basis of defined ad-hoc parametric spatial rules capable of representing urban phenomena, modelling the historical stratifications of the city and evaluate how these layers can interact within a three-dimensional modelling environment in order to replicate past and simulate future transformation and sustainable scenarios through platforms adoption dedicated to urban simulation.

In particular, the research, in this first phase, worked in three specific directions.

  1. DATA. The collection and harmonization and updating of geographical datasets data and thematic data available on the city of Turin (FULL metadata index) for the structuring of a multi-scale and multi-content geodatabase. The experimentation of data acquisition and processing of data from mobile mapping systems at the urban scale. The collection and use of multi-temporal datasets on the city of Turin by means of historical aerial photogrammetric datasets, and consequent correlation of multi-temporal DSMs for the detection and assessment of urban transformations (Abate et al., 2019).


  1. 3D MODELS. The treatment of aerial Lidar / photogrammetric data in the form of raster/vector DSMs for the integration of information related to the roof shape and trend. The investigation of GIS-BIM tools capable of managing multi-scale modelling and able to ensure increasingly interoperability between the two systems and relative languages and standards. The generation of simplified 3D models with semantic content and with floor-level optimized information structure (See ROCK project and Technical Report).
  2. VISUALIZATION. The development and optimization of spatial analysis tools and data representation strategies through 2D, 2.5D, 3D spatial visualization (ROCK project).


  • Abbate, E., Sammartano, G., & Spanò, A. (2019). Prospective upon multi-source urban scale data for 3D documentation and monitoring of urban legacies. ISPRS – International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, XLII-2/W11, 11–19.

  • Colucci, E.; Mantello, F.; Spanò, A.; Sammartano, G.; Abbate, E. (2019). Approcci GIS ed HBIM integrati per l’analisi del patrimonio paesaggistico. 23a Conferenza nazionale ASITA, 12-14 November 2019, Trieste (Italy)

  • Technical Report “Which digital tools for the creation of a Digital Open Urban Twin?”, progetto di ricerca DOUT (Digital Open Urban Twin) resp. Antonio Vetrò

  • Technical Report Progetto ROCK “Mappatura e analisi di proprietà e aree dismesse a Torino nell’ambito del progetto europeo ROCK – Regeneration and Optimization of Cultural Heritage in Creative and Knowledge cities (GA 730280)  finanziato dal programma Horizon2020 – CIG: Z78280839F”. Intermedio 26/11/2019. Finale 06/2020