Digital Preservation in Volterra

Earlier this year, the Volterra-Detroit Foundation hosted an International Digital Preservation Workshop in Volterra, Italy – its eighth workshop since 2016. There, more than a dozen professionals and students from around the world gathered in Tuscany for two weeks to collaborate, learn, and share best practices in reality computing, using a wide range of emerging technologies to capture, compute, and consume historic and cultural artifacts.

Having previously used aerial photogrammetry and Virtual Reality (VR) on landmark preservation and sustainability projects in Micronesia and Fiji, I built on that experience to capture and document ancient ruins, medieval structures, and modern alabaster studio when I first participated in the workshop in 2022. This year, I returned to Volterra specifically to explore Mixed Reality (MR) to enable experiences of virtual reconstruction of ancient ruins.

We set out to explore how MR can bring value to municipal administrators, historic preservationists, and AEC professionals by experiencing digital reconstructions overlaid onto a physical site, in-situ and at full scale. Seeing and walking through digital data on site, beyond looking at a plane of glass on a monitor or tablet, enhances our understanding of the past in the spatial context of the present. It also supports effective decision-making on site about future actions, where it matters most.

My intention was to test this hypothesis of the benefits of MR in reconstruction using Volterra’s ancient Teatro Romano (Roman Theater) ruins as a pilot project. Before leaving home for Italy, I test-loaded models created in Autodesk Revit and 3ds Max into Arkio loaded onto a Meta Quest 3, to align them to a map of Volterra, and experience them in MR at reduced scale in my home office and front yard. Satisfied with those initial tests, I packed up my tools and headed to Tuscany!

Starting at the World’s Oldest Arch

On the first day of the workshop, we were given a tour of Volterra by the school administrator, who brought us to the Porta all’Arco, Volterra’s famed “front door” built by the Etruscans in the Bronze Age, and widely considered the oldest standing arch in the world. The Porta all’Arco was originally adorned with three sculpted heads at the keystone and springs of the arch. The administrator granting the tour lamented that the sculptures had been lost to time, and all that was left were severely weathered, lumpy stones. She also shared that the stones were originally sculpted with the heads Zeus, Castor, and Pollux, as evidenced by only one remaining historical artifact: their heads on the arch were depicted in a chaotic battle scene carved into an Etruscan alabaster funerary urn, exhibited today at Volterra’s Etruscan Museum.

Our first exercise in the workshop was to try our hands at object photogrammetry, capturing hundreds of photographs of an object and using Autodesk Recap Photo to reconstruct the 3-D object digitally and output a mesh model. One of the other workshop students, my son Arlan (17), was inspired to try capturing the Porta all’Arco. Despite warnings from the instructors that the complexity of the arch would not likely be well captured using object photogrammetry, he pressed ahead with his ambitious plans. With some careful planning assistance by his father, he accurately documented and faithfully reconstructed the Porta all’Arco as a 3-D mesh – a “proud papa” moment! – and we imported the model into Arkio for a quick full-scale walkthrough in VR.

Inspired by his efforts to document the oldest arch in the world, I decided to focus my attention on reconstructing what little is left of the three sculpted heads of Porta all’Arco, to see if we could experience them spatially overlaid onto the arch. So I ventured off to Volterra’s Etruscan Museum to document the depiction of the heads carved into the alabaster funerary urn. The urn was well-preserved, and on exhibit behind thick plate glass casting harsh reflections from museum lighting. Despite these limitations, I successfully captured the urn with several dozen photos, processed them using object photogrammetry in Recap Photo to create a mesh model, and then edited, trimmed, and isolated the three heads from the battle scene carved in alabaster.

From Recap Photo, we exported OBJ files of the full-scale arch and the scaled carvings of the heads, and I imported these into Arkio, aligning them to the weathered stones to experience the reconstructed arch at full scale – with Zeus, Castor, and Pollux looking down on us.

It was impressive to walk around and through the arch and reconstructed heads in VR. Next, it was time to bring the model out to the site to experience them in MR. We charged up the battery to the headset, and headed to Volterra’s front door, where we once again loaded the models of the arch and heads into Arkio. From there, we manually moved the virtual model to align to the physical world, and locked it in place with Arkio’s anchoring tools.

After that, it was easy to hide the model of the arch, leaving only the virtual reconstruction of the three heads superimposed in space over the physical arch! It was amazing to experience this at full scale, to walk around the physical Porta all’Arco and see the three original faces that had been lost to time, overlaid directly onto their original perches at the keystone and spring positions.

We weren’t the only ones excited by the success, as a film crew documenting the impact of the workshop on Volterra rushed to include our efforts and results, featuring my son walking around on site. To top it off, the VR experience of the arch was featured in a public open house exhibition at the end of the workshop, where the mayor and dozens of officials and students got to experience the virtually restored Porta all’Arco at full scale!

Let’s Go to the Theater

As exciting as it was to virtually reconstruct the sculptures adorning the world’s oldest arch, I sought to build on that success with my original interest in the Teatro Romano. Volterra’s Teatro Romano has been the focus of much study over the past several years, and scholarly analysis of the Volterra-Detroit Foundation’s documentation of the ruins have led to exciting discoveries and theories about the proportions and rules of ancient Roman architecture. While only a fraction of the original theater structure is left standing, there are sufficient ruins on site that past workshop efforts had successfully yielded a fully-developed digital model of the original architecture.

Fellow workshop students shared their latest version of the reconstructed theater model as a GLB file, which I also imported into Arkio. After some easy scaling adjustments to the units, and alignment to the city map in Arkio, I ventured out to the theater ruins site. From an overlook point along the medieval city wall, I loaded the theater model in Arkio on the Quest 3 and quickly aligned it to the ruins of the theater wall and seating bowl.

The results were impressive, to say the least! The remaining theater ruins and seating bowl leave the impression of a facility low and depressed into the terrain, which is quite misleading: the original theater was a three-story facility, plus a retractable shading structure, that towered over the landscape and rose to the height of the overlook from the medieval city wall. The size of the virtually reconstructed structure at full-scale was massive! It completely changed the perception of what had been there in the past, compared to what you would infer from the physical ruins alone.

Excited by this realization, I returned the next day with fellow workshop instructors and students. This time, we set up inside the ruins, along a central circulation corridor between the lower and upper seating bowls. After another quick model alignment, we excitedly walked around the theater seating to experience the virtually reconstructed Teatro Romano from within the complex, and at full-scale.

We experimented further with Arkio’s various rendering modes and section-cutting tools to get a better understanding of the relationship between the physical ruins and the virtual reconstruction, as well as the relationship between the various theater levels and spaces.

My colleagues’ reactions were best described as amazement and awe. For years, staff and students at the Volterra-Detroit Foundation have brainstormed ideas to provide the public with a way to visualize the virtually reconstructed theater on-site from discreet, fixed locations. Yet, here we had done it in a way that allowed people to experience the Teatro Romano spatially by walking around freely, interactively, and immersively with Mixed Reality!

Mixed Reality for All

The implications of using MR to experience a virtual model on a project site are enormous for both historic preservationists and AEC professionals. By eliminating the guesswork and abstraction of 2-D diagrams and scale models, and overcoming the limitations of static renderings, MR allows us to experience past or proposed future conditions with our innate spatial abilities.

Mixed Reality democratizes access to complex spatial design data, presenting it in ways that anyone can understand, and enabling effective decisions about preserving, designing, building, and sustaining our built environment for future generations.

Dace Campbell, AIA, LEED AP, Industry Strategist

Dace is a professionally licensed architect and consultant with extensive experience developing and implementing strategy and innovation. He helps AEC firms realize tangible business results from their investment in XR technology, and XR tech companies land and expand in the AEC industry.