By Eric Pecile

Since the fall of 2018, I have been developing a 3D GIS of Florence for the DECIMA platform. At the start of 2017, our GIS existed only as a street map with appropriately georeferenced blocks aligned to Florence’s terrain. The next step was to experiment with creating models of the city’s buildings. We wanted to show both the historical structures (old buildings that exist in the same geographic configuration that they do today) and the those buildings that have been changed over time, to ensure we had a map that resembled the Buonsignori map as closely as possible. Congruency between Buonsignori’s 1584 aerial view and our 3D recreation would allow the census data to be re-projected more easily. However, modelling an entire city from the ground up would be a time-consuming task even with the use of City Engine software which could help automate much of the process. To overcome this issue, DECIMA purchased a 3D rendering of modern Florence from Cyber City. From this massive model, I gradually removed the modern structures and features of the city using ArcGIS Pro. The remaining clusters of city blocks were then uploaded into City Engine, comprising what is currently the alpha version of the 3D GIS (see fig.1).

Fig 1. Screenshot of the DECIMA 3D alpha.

Currently, this 3D alpha is being proofread for compliance with the 1584 Buonsignori structural visuals. Block by block, the number of structures is being checked for congruency with its equivalent on Buonsignori. If there are too many structures or too few, the block is deleted and replaced by a cga 3D rule file designed to reflect Buonsignori’s building configuration. Most of the digital labour at this stage is the coding of new cga files that best represent blocks as represented by Buonsignori. This process brings this GIS closer to a beta stage where it will be ready to upload to the web GIS and have the census data projected onto it.

To give a fuller discussion of this process and the thinking behind it, I have published an article in the on-line Italian journal Disegnarecon. “Respecting Historical Spatial Integrity: Building a Historical 3D Florence and Avoiding the Video Game” was included in the journal’s special issue on “Advanced Technologies for Historical Cities’ Visualization.” This issue explored the technological considerations and research processes that go into digital work on urban environments, predicated upon reconstructing historical space in computational environments. In my article on I outlined the workflow going into DECIMA 3D, elaborated on the theoretical and methodological considerations that accompanied the output process, and sketched the discussions among DECIMA researchers and the teaching experience that we developed in a program at the University of Toronto meant to bring undergraduates as researchers into digital projects (STEP Forward). Other articles in this issue of Disegnarecon explored similar issues and showcased how to optimize the use of diverse software to preserve the historicity of digital recreations. You can find the article at this link:

Fellow DECIMA Research Assistant Hana Suckstorff and I also participated in the 2018 and 2019 Digital Art HistoryWorkshop organized by the Visualizing Venice project and supported by the Getty Foundation. The workshops brought together digital humanities scholars from a variety of projects in order to create a digitally focused intellectual community where scholars could help each other solve research problems, troubleshoot existing technologies and compare digital output results. The 2019 workshop was dedicated to determining how to produce hands-on tutorials that would allow teams to demonstrate how to use the software they have employed in their own work. As Hana Suckstorff has reported elsewhere, DECIMA collaborated with members of the Firenze Scomparsa team by sharing its street block map. We hope that this allows them to create an independent 3D model in whichever software they chose, and to delineate a block polygon in the City Engine map to anchor their model and possibly share it in the DECIMA’s web GIS database. Collaborating in this way helps other geospatial historical work on Florence to come to fruition and ensures DECIMA’s use as an open source publication platform for GIS based work on the city.

By September 2019, DECIMA 3D will be in its beta stage. More proofreading of the cga files will be required to ensure Buonsignori congruency before census data is projected on it, and in the interim we can benchmark the hardware requirements for the web GIS and determine the optimal way to format it. I will also be partnering with Stephen Whiteman from the Visualizing the Mountain Estate on a publication about representing ambiguity in digital environments. Stay tuned for further updates on the format and timeline for a collaborative DECIMA publication!