Rialto Bridge 3D Modeling

Historical Background

The Rialto Bridge, is nowadays a symbol of Venice and one of the four main bridges crossing the Canal Grande. The island of Venice is divided in two parts by the Canal Grande, the greatest Canal of Venice and its main maritime route, which is 3800m long and has the peculiar shape of a large reverse S.  Furthermore, it is important to highlight that the Rialto Bridge is built on the narrowest point across the canal and connects the districts of San Paolo and San Marco. The Rialto Bridge has been the only way through which one could cross the canal by foot until the construction of the Accademia Bridge in 1854, but still nowadays it acts like the most common and practice way to move within the districts. The other main bridges in the city are: the Accademia bridge, Scalzi bridge and Costituzione bridge. Among these, the Rialto is the most ancient one, dating back at the XII century. The other 3 bridges would have been built only in the XIX century.

- Venice, Canal Grande top view.
–  Venice, Canal Grande top view.

Architectural Insights

Rialto bridge connects two vital areas of Venice: the financial and commercial center of Venice on one side and the poilitcal centre on the other. The very first version of the bridge was a boat bridge, which was soon replaced by a real wooden bridge. The latter one was conceived with a lifting central part which allowed the greatest merchant ships to pass through the bridge.

Schermata 2014-12-17 alle 15.06.52
–  Venice, Rialto wooden bridge

The wooden bridged revealed to be extremely subject to damages like fire and showed a lack in structural resistance. That’s why in 1503 the first proposal of a stone bridged has been promoted. Nonetheless only in the half of the XVI century a competition annoucement has been held. Among the proposals, there had been projects form famous arhcitect like Jacopo Sansovino, Andrea Palladio and Il Vignola.  In the end and after many vicissitudes, Venice chosed to realize Antonio da Ponte’s project. This is the version we can still admire nowadays. It is important to highlight that the actual design of the bridge recalls the former wooden predecessor. In fact, Da Ponte’s design of the marble structure has two sloped ramps leading to a central portico to allow the passage of tall ships.

- Venice, Rialto bridge as it appears nowadays.
–  Venice, Rialto bridge as it appears nowadays.

One of the architectural challenges for this bridge was that the canal banks are not above the water level. This means that an usual acrhes structure typical for example of the roman bridges doesn’t fit the Venetian environment. In order to build arches it’s necessary to build an upward sloped bridge in order to have room for the arch and this explains the presence of the ramps. Another curious architectural insight deals with the design of the path. The Rialto bridge has three paths: one wide central walkway which has shops on its either sides and two along the railings of the bridge. The capacity of the bridge pleased the business-minded Venetians which was one of the reasons for choosing Da Ponte’s design. The stone reliefs on the bridge depict the city’s patron saints St. Mark and St. Theodore and the Annuciation. Along with St Mark’s Square, Rialto Bridge is the most visited tourist spot in Venice.

Objectives and Deliverables

The idea that the Rialto bridge could have been completely different is very enthralling. A different version could have brought to a different development of the city of Venice, both from an urban and a social point of view. In this framework we insert with our project aimed at analyzing this possible alternative Rialto versions. The main objective would be to create 3D models of 3 of  the main alternatives of the realized bridge, trying to extend the model to the nearby areas of the district affected by the projects. While doing so we’ll try to carry on an analysis of the possible social/economic/urban consequences of the alternative projects. In particular we’ll focus on the Palladio’s project for its peculiarity. With this objectives in mind, the deliverables will be a poster where we’ll present a sort of timeline of the bridge and the 3D recreated versions. In addition we’ll present also a video with a virtual tour of the 3D models created. Finally we’ll write a brief report with some thought about the consequences of the realization of the Palladio’s project. A sort of “what if “ with our thoughts about the possible outcome of a different hystorical choice. We’ll also try to transpose some of the information about the versions in a CGI project, trying in this way to inegrate the model with the real map of Venice.

- Rialto bridge's project from itaian architect Palladio.
–  Rialto bridge’s project from itaian architect Palladio.


All the practical work will be preceded by mens of a preliminary study of documentations founded in literature. Our main resources will be:

  1. “Rialto: le fabbriche e il ponte”, by Donatella Calabi and Paolo Morachiello;
  2. “Public buildings in early modern Europe” by Deborah Howard.
  3. “I quattro libri dell’architettura” by Andrea Palladio.

These books will provide us in first place with a deeper knowledge of the history of the bridge and the reason that brought Venice to chose da Ponte’s project and reject the other ones, including the three we’ll model. In particulat, the first reference will be a fundamental source for all the iconographic documentation will need. In fact we can find the original projects, or reconstruction of them, drawn by the architects we chose for the 3D models. There are front view, side view, maps and studies of the component of the bridge made by the authors. All these information will be integrated and developed in our 3D models. The models will be created using the software SketchUp, that is basically a general-purpose 3D content creation tool, by which it is possible to create volumes starting from 2D planimetry and then extrude. Sketchup also include a specific tool that stands us a mobile viewer and allows a first-persone diving into the model.

Schermata 2014-12-17 alle 13.33.36

Once we have the three models we can start to work to two of our deliverables: the poster and the video. With the poster our objective is to show a timeline of the Rialto birdge. The idea is that the time will follow one line up to the moment the reality splits into the three alternatives version of the bridge. On th other side, using SketchUp will create a virtual tour of the bridges we built. Both the derivable are conceived to convey the idea of how different the reality could be, even looking at just a bridge. Along this concept will deeper analyze the Palladio project. This choice is motivated by the fact that thanks to Palladio’s “I quattro libri dell’architettura” we have plenty of information about his project. Moreover, Palladio’s version of the bridge was more extensive than da Ponte’s one. In fact he planned to create two courts in front of borh side of the access to the bridge. This would have meant that the surrounding area would have neede to be completely rebuilt, with important consequences from an economic, urban and social point of view. Moreover the direction of the Palladian bridge is not the same of da Ponte’s one, this could have also created more urban differences. Our objective here is to try to take into account each of these aspects and think about the their possible historic consequences. Finally we want to develop a CGI project using QGIS 2.6 Brighton. The idea here is to create basic level of Venice and then add historical information and images of the alternatives version of the bridge.


In order to structure our plan we thought at the time available in term of weeks: 14 for the entire semester. We started to define milestones from the end of this period. In fact our first point is the 12th week: by this time we want to have already developed roughly everithing. In this way we’ll have 2 weeks to review everything and think about the details. With this goal in mind we can go through the rest of the weeks. Weeks 1 and 2 will be used to gather and study the iconographic documentation. in this period we want to get a better idea of the history behind the bridge and to collect all the quantitative data to be used for the 3D modelling. The following 7 weeks will be used to develop in SketchUp the models. The idea is to allocate 2 weeks for each of the three models plus an additional week for the Palladio’s version used to write down the “What if” analysis. Once we have the models, the following 2 weeks will be used to produce the poster and the video. The 12th week we’ll be used to develop the GIS project. As stated above, the last two week we’ll be used to finish the project if we’ll be late, otherwise we’ll use this time to refine the work done.


- Work-Plan's Gantt diagram.
–  Work-Plan’s Gantt diagram.

Biancolillo Marco Liborio

Flores Omar