Digital Art Histories: 3D (Geo)Spatial Networks
Fortifications of the City of Trogir: Visualizing changes from 220BCE until 1900CE
Final Project Update and Reflections
Ana Plosnić Škarić and Ana Šverko
The project Fortifications of the City of Trogir: Visualizing changes from 220BCE until 1900CE, is part of a long-term study of urban history conducted at the Institute of Art History (IPU), Croatia, since 1961. It is part of the IPU Strategy, and from October 2019 its duration has been extended to October 2023. The project evolved from more than twenty years of research of the city of Trogir’s urban history by both APS and AS investigators. As such, it is predominantly focused on developing a methodology for visualizing research results. The work on the project was distributed around the year 1500, due to the investigators’ prior expertise and the quantity and quality of sources available. Therefore the visualization methodology is being developed in two ways.
The methodology applied for the visualization of the changes of the fortifications until the year 1500 was concentrated on 2D representations–more specifically on the use of QGIS program. It is important to say that the fortifications are preserved only in a few parts. Therefore the research has been primarily based on collecting the sources and interpreting them in terms of location, period and style. By June 2019, the QGIS database was created. It is structured in several layers, selecting polygons, lines or points according to the nature of the mapped source (preserved built structures, archaeological findings, historical maps, vedute, architectural drawings, photographs, data from historiography, and data from archival documents). Each layer has an attribute table with data arranged in several columns. Such a GIS database is suitable for the creation of a large number of maps, in accordance with the research questions posed by the user. It is also suitable for further extension.
As part of the project, the original purpose of this database was to produce analytic static maps. These were meant to be available on the project website, along with sources they analyzed. This kind of presentation of sources that includes their interpretation is essential to any study of urban change. Therefore, the project’s output can be recognized as a model that can serve structure information that applies not only to the fortifications but also to the entire city of Trogir. Furthermore, the model could be applied to other Dalmatian cities. The aim of such databases would certainly be to facilitate research. Available sources available up to 1500 are always preserved in fragments and these fragments differ for each Dalmatian city. Having some information about one city can be the key to understanding a particular process in another. Such databases would significantly facilitate research.
Although the aim remained the same, thanks to the DAHVenice Group discussions, it was decided to move from analytic-static to analytic-dynamic maps, which would include sources available in pop-ups. All the analytic maps, structured in layers, are meant to be presented through a single interface, thus enabling cross-comparability, and QGIS is to be exported to Leaflet. However, the main mapping and map-making processes remain the same. Although both processes are recognized as subjective and creative, the one that emerges as more challenging is the map-making. This conclusion came after mapping the data from historical maps. That mapping inevitably involves learning from historical maps. The georeferencing process found most of these maps highly inaccurate. But is it precisely the inaccuracy that made it possible to highlight the most important parts, which enables a clear understanding of the drawn data (as well as circumstances and purpose in which and for which they were drawn). Working in GIS, of course, doesn’t allow these kinds of inaccuracies, therefore designing the maps arises to the key challenge, in order to provide effective communication of the contents.
So far the work on this part of the project has focused on the presentation and interpretation of the preserved sources. It is new programs that can offer opportunities to structure these data in ways that may not have been possible just a few decades ago. However, further challenges arose from the discussions held on June 2019. It is the question of narrative. The narrative to be incorporated would represent the development of the fortifications (and subsequently the development of the entire city of Trogir). It would be also necessary to explain political and social circumstances in which certain parts of the fortifications were erected, furtherly used, or dismantled–defining the social groups, institutions, and their prominent representatives, responsible for these changes. In this regard, it is worth following the good advice and exploring the possibility of timelines plugins for Leaflet. Incorporating the narration with its political and social context into the same and only interface is an additional task.
Although the methodology of project visualization up to the year 1500 remains in the domain of 2D, experience with the DAHVenice Institute prompts further challenges, especially when the narration is intended. Most notable stories are always personal, and the material collected provides a wide range of prosopographic insights. In this regard, all visualizations regarding moods, agent-based movement, AR experience, etc. remain challenging–but their feasibility would depend on the ability to extend the project team.
The methodological area used for the visualization from 1500 – 1900CE is based on spatial analysis, mostly through digital mapping visualization and 3D modelling. This methodological area allows us to create historically informed visualizations and makes it easier to create well-argued assumptions for an entire reconstruction of the historical changes. In addition, this methodology offers an excellent tool not only for mapping changes but for researching the causes and consequences of those changes.
This workshop helped us to develop our work in two different directions: contribution to the art historical research topic that we choose, and contribution to the field of digital art history in general. From the one side, we have developed our knowledge about the historical transformation of fortifications of Trogir during the long-time period; through stylistic and morphological transformations in line with social, political and economic changes. So we are able to individually publish the results of the research process, which were reached by use of digital tools and methodology that we developed. But on the other hand, and in light of our workshop, much more important result is new methodological approach, that is worth to be published together with other projects developed in this program. We believe that all our approaches together will make important contribution to the field in terms of collections of applicable technologies and methodologies that could be applied to other similar researches. That kind of publications could be first of the kind (as far as we know) that could be useful to experts in the field but also to art historians that are still not aware of possibilities of digital methodology.
The investigators of Trogir’s Fortification project owe their gratitude to the organizers, all the participants and the supporter of DAHVenice Institute for all the presentations, readings and discussions from which we were learning and will continue to learn.