The archaeological site of Liternum restored by ACCA software through site surveying, points cloud and BIM technology
Located in the area north of Cuma, Liternum was founded in 194 BC together with Puteoli and Volturnum, as a maritime colony on the left bank of Lake Patria and assigned to three hundred veterans of the second Punic war. The town is mainly famous as a residence of the Roman general Publius Cornelius Scipio the African, who withdrew in exile from Rome and was buried there.
A reconstruction model of the archaeological site, generated through the combined use of a BIM software (Edificius) and a collaborative platform (usBIM.platform), has been recently presented in Rome during the Word Tourism Event 2019.
The advanced reconstruction project was carried out by the Italian-based company ACCA software producing astonishing results that could be navigated in an immersive virtual reality scenario of the entire site.
Liternum, site restoration
The whole process is based on 3 fundamental phases:
- the surveying of the current situation: starting from photos taken with a drone, digital photogrammetry was integrated, thus obtaining the point cloud and the mesh pattern with the existing texture
- 3D virtual reconstruction of the ancient Liternum: after a careful archaeological study, the model was reproduced using a BIM architectural design software
- federation of models: the 2 models are federated thanks to the use of a special BIM platform.
The Liternum archaeological park consists of 7 main components.
The Forum was the center of public life in any Roman city. It had a rectangular shape with north-south orientation and was crossed longitudinally, from south to north, by the ancient route of the Via Domitiana.
It was almost entirely surrounded by a colonnaded portico with a series of Tabernae (shops) and the most important civil and religious buildings of a Roman colony:
- the Basilica
- the Capitolium
- the Theatre
What is left today of these buildings are mainly ruins outlined by their planimetric layout.
The Basilica stood south-west of the Forum and served as several functions, including a courthouse and meeting hall for magistrates. The 32-m x 23 m building with a single nave plan had the internal hall decorated with half-columns.
Today, the building perimeter built with an opus reticulatum technique (wall layer with diamond-shaped tufa blocks) is the remain of the Basilica that is dated back to the late Republican age.
The town Capitolium, dating back to 194 BC, was located north of the Basilica in a central and scenographic position on the Forum. It had a 17-m facade and a 23-m side.
The main temple of the city was dedicated to the Capitoline Triad: Jupiter, Juno and Minerva. It had a cell with three niches for the cult statues. A portico with 4 frontal columns (prònao tetràstilo) of Corinthian order leaded to the cell.
The high base of the temple (podium), that was built with the opus incertum technique (wall layer in different-sized tuff stone) with wall joints in opus reticulatum and opus latericium (coarse-laid brickwork), still survives in situ with a restored column, a capital and a few fragments.
The Theatre, built during the imperial era, stood on the north side of the Capitolium. The small auditorium (stairs for spectators) had a diameter of 40 m and could have a capacity of about 1,000 people.
The auditorium rested on a wall basement in tuff (substructure) and was accessible externally through three flights of stairs (vomitoria). Only few traces of the two low steps (proedria), which are accessible directly from the theatre orchestra and where the city elders seated on single wooden seats (bisellia), are left of the entire auditorium stairs.
In addition, only a few masonry fragments remain of the monumentally decorated permanent architectural background (scenae frons) built in opus vittatum (regular wall layers in tufa blocks) with rows in opus latericium (terracotta brick wall layers).
A series of Tabernae (shops) were located on the opposite sides of the Forum. Often these commercial premises had a mezzanine which hosted the shopkeeper’s lodgings.
In the ancient Roman cities, commercial activities represented one of the most lively and fundamental aspects for the material existence of citizens. Artisans and merchants formed real corporations capable of exerting their influence even during the elections of magistrates of the colony.
Among the most important guilds there were the fullones (launderers), the coactiliarii (felters and fullers), the pistores (millers and bakers), the pomarii (fruit shops) etc.
Today some of these structures are found on the north side, where there are masonry fragments at the base in opus reticulatum.
The only monument of the Forum that remains in good condition is the so-called Scipio’s Tomb, made of volcanic stone.
The small monument is a sort of cenotaph (symbolic, empty monumental tomb), erected in honour of the famous military commander who defeated the Carthaginians in the Second Punic War, Publius Cornelius Scipio “the African”.
The Via Domitiana
The Forum of Liternum was crossed from north to south by the Via Domitiana.
The Via Domitiana, originating from the ancient Via Appia, was named after the Roman emperor Domitian who promoted its construction in 95 AD This great route improved the connection between the port of Puteoli (Pozzuoli) and the rest of the empire.
Currently the modern state road partly follows the ancient route.
The surveying and digitalization of the current situation
The current situation has been surveyed using a commercial drone, which took a series of photos and videos. The photos were taken following the classic rules for photogrammetry. For the purposes of the project it was not necessary to integrate the survey with a laser scanner.
In the next phase, photos have been processed with a suitable photogrammetry software, obtaining point cloud and textured meshes. Then the OBJ model (textured mesh) has been appropriately scaled.
Subsequently, the OBJ model has been divided into 7 main components:
- Scipio’s Ara
- Via Domitiana
Finally, the model has been uploaded on the collaborative BIM platform usBIM.platform.
Each of the 7 components of the model has been associated with a PDF card with relating information.
The model could be navigated directly from a browser (e.g. Google Chrome), without the need of any specific app.
Exploring the reconstructed 3D model in a VR environment
Thanks to the innovative usBIM.VR technology, it is possible to navigate the entire model in an immersive virtual reality environment. It is sufficient to have a common VR viewer (ex. Oculus Rift S or HTC Vive ) to explore the park and even walk within it.
Even when a VR viewer is not available, it is possible to enable the navigation of the rendered model in real time, thanks to the new usBIM.reality technology, which allows you to change the lighting and sunshine conditions and set up time and date (to determine the actual position of the sun and the shadow projections throughout the day).
Moreover, it is possible to apply the clouds or rain effects, which will “wet” the existing textures in real time, without having to re-render them. The result is stunning!
Reconstruction of the BIM model and model federation
Thanks to the site surveying, it was possible to reconstruct the BIM model (hypothetical) through a set of information with Edificius (the architectural BIM design software) bringing back to life the ancient Forum, the Basilica, the Tabernae, etc.
After creating the model, the file was uploaded to the platform, thus obtaining:
- current situation – .OBJ surveying
- reconstructed BIM model in .EDF
Moreover, thanks to the platform functions it was made possible to “federate” the 2 models. The federated model obtained is really impressive, especially if specific transparencies are used on the existing model.
Finally, it was once again possible to view the models, single or federated, in immersive virtual reality.
Video of the Liternum archeological park digitalization
Below you can see the explanatory video of the Liternum archaeological site reconstruction project.