Ullastret3D. Walking through an Iberian town from 2.200 years ago.

1. Ullastret, a 2.200-year-old Iberian Town

The Iberian town of Ullastret (6-2 B.C.) is located on today's Empordà plain in Catalonia, Spain, and is one of the most well-known and outstanding iron-age archaeological sites of the north-west Mediterranean. This large urban settlement was formed by two inhabited centers, one being the Puig de Sant Andreu (Saint Andrew Hill) and the other the Illa d’en Reixac (Reixac Island), separated, one from the other by a distance of only 300 meters. Between them, the two settlements eventually extended over a walled area exceeding 15 hectares and they constituted the capital of the Iberian tribe known as the Indiketes.

The site was discovered around 1930 but it is the research that has been carried out over recent years, based in many cases on the application of the latest generation of geophysical prospection techniques that has produced the greatest knowledge with regard to its urban and defensive structures and the surrounding area. This has enabled us to devise and support a project for the virtual 3D reconstruction of the entire settlement based on very sound scientific knowledge which, in turn, has benefitted from the important advances made in the study of Iberian culture over recent years. Because it is the best-known period from a scientific point of view, the reconstruction focuses on a specific moment in the settlement's history, around the year 250 B.C.

2. The process of virtual reconstruction

A multidisciplinary team was established to implement the project. The team was directed by the Museu d'Arquelogia de Catalunya-Ullastret (Ullastret branch of the Archaeological Museum of Catalonia) and was coordinated at a technical level by the Agència Catalana del Patrimoni Cultural (Catalan Agency for Cultural Heritage), which worked together with the graphic design and 3D modeling studio, Burzon*Comenge. Additional assistance was received from a large number of specialists in various fields, such as architects, anthropologists, hydrogeologists and naval architecture specialists, in order to define the multiple aspects under consideration to produce this reconstruction with the greatest possible detail, precision and scientific rigor.

The first step in the reconstruction consisted of an exhaustive compilation of all the available archaeological information. Nevertheless, it should be borne in mind that, on occasion, we have had to employ comparative, theoretical and/or experimental models and that, in some cases, these have not been archaeologically proven. While they are based on well founded hypotheses, they will always be subject to future revision.

Once these data had been validated from a scientific point of view they were thematically categorized and passed on to the design studio responsible for their virtual 3D texturing and modeling in accordance with a pre-established work sequence and the guidelines were inspired by the London Charter. In this regard, the first aspect under consideration was the geomorphological structure of the settlements and the paleo-landscape, given that it was of fundamental importance to locate the settlement within its geographical context.

Some of the important aspects to be borne in mind when modeling the landscape were the kind of vegetation that would have existed at that time and, especially, the transforming effect of human activity arising from the creation of access routes, agricultural exploitation, the extraction of mineral resources, and so forth. The next consideration was the structure of the settlement itself, firstly based on recreating the defensive structures (wall and trench), and then by considering the urban layout to determine the position of the streets and thoroughfares, so as to recreate the individualized three-dimensional volumes of the various kinds of buildings and other constructions in the settlement.

Finally, movable elements of the buildings' interiors were reconstructed and incorporated, in addition to other kinds of artifacts, based on real items of Iberian culture found during excavations, such as the amphorae, pitchers, tools, swords and shields which now form part of the collection at Ullastret Museum. Similarly, on the basis of comparative research, other organic elements, of which there are consequently no archaeological remains but which we know existed via other means, were also reconstructed.

At a technical level the model was built using 3D maps, provided by the Cartographic and Geological Institute of Catalonia, which make possible to generate a geometrical mesh to represent the lie of the land. However, the lake of Ullastret, which was drained in the 19th century, had to be reintroduced virtually. Three-dimensional outlines were made using the Cinema4D and 3D Studio Max applications, mainly in order to reproduce the landscape and its architectural features. Objects were mainly reproduced from vectorized drawings exported to a 3D format from which Maya software generated the model, adding texture and color. All these models of terrain, vegetation, pathways, the lake, buildings and objects were then imported into the Unreal Engine 4 game engine which is outstanding for its ability to create landscapes and for the photorealist graphic quality it gives to images, in this case by means of textures created from photographs of real things (Making of 3D reconstruction).

These software also enables the relatively simple export of the entire project to immersive virtual environments such as for multiscreen projection, 360º video, and most especially, for virtual reality headsets. As the virtual models were being produced they were checked for scientific accuracy right from the outset when only the volumes themselves were being represented, and then throughout the entire working process up to the production of the hyper-realistic image. This procedure made it possible to introduce any necessary corrections along the way, and some of these corrections meant that some of the preconceived ideas about Iberian settlements. In effect, what Ullastret 3D has enabled us is to create a new image of the Iberian town and to make it available to the general public in a very powerful and accessible way.

3. The outputs: Internet, Immersive Room and Virtual Reality Experience

After almost a year and a half of intensive work the first phase of the project concluded with the creation and dissemination, via social media, of a video of the 3D reconstruction of the Iberian town. It was very well received and had more than 30,000 visits. Nevertheless, the aim of the modeling was not limited to the creation of this visual representation. After evaluating various options from the technical and economic viewpoint it was decided to develop two practical applications. An immersive room in which to project an audiovisual of the virtual reconstruction, and an adaptation of that reconstruction for viewing with virtual reality headsets.

The project undertaken at the Ullastret branch of the Archaeological Museum of Catalonia consists of a multi-screen projection visible on three of the room's four walls, which is accompanied by a three dimensional audio system synchronized with the movement of the images. Together they create an enveloping effect for viewers. A great deal of work has gone into the production of the sound so that it achieves a sonorous texture that matches the various virtual spaces that appear in the projection. The aim is for the room, which covers an area of approximately 10 square meters, to be able to reproduce the dimensions and characteristics of an ordinary Iberian dwelling, such as those which appear in the projected audiovisual, as accurately as possible. The room is used to project a six-minute-long audiovisual that consists entirely of a journey through a digital model, filmed with virtual cameras. Viewers make a dream-like journey through the Iberian settlement, passing through its streets and empty houses. The story is narrated by a former inhabitant, a member of the elite, who remembers dramatic moments in the settlement's history. In this regard an attempt was made with the concept and narrative structure to avoid the traditional format of a lineal, descriptive audiovisual with a description and contextualization of the settlement. The audiovisual is therefore conceived as a tool that is especially useful for enhancing people's knowledge about this settlement, as well as their ability to interpret it (Making of the Immersive Room).

The audiovisual created for the immersive room was adapted, in collaboration with "Visyon", a VR and 360 production company, to create a version for the HTC Vive Virtual Reality headset. These devices, unlike the immersive room, make complete, and absolutely realistic, immersion possible because viewers can navigate within the virtual space in a natural way and at a life-size scale. Thus far it has been used to present Ullastret3D at specialized congresses such as Arqueológica 2.0, Valencia; Archeovirtual, Paestum, Italy; and so forth, and at popular events to raise people's awareness about their cultural heritage, such as the Museum's Night held in Barcelona and the Iberian Weekend, held in Ullastret, to name but two. During 2017 it will become a permanent feature at the Archaeological Museum of Catalonia in Barcelona.

4. Narrative

As work started on the immersive outputs, a detailed study was undertaken to determine what kind of narrative would be most appropriate for this medium. A thorough study was made of existing 360º videos and available virtual reality experiences. It soon became clear that a traditional narrative would not be the most suitable. In our case it was essential to create a story that would justify the spectator's presence in the most important places in the settlement. It was also necessary to use visual and auditory resources to guide the spectators' gaze so that they might best explore this virtual environment. The script also had to contain key elements of Iberian culture such as the inhabitants' totemic animals, the social prevalence of warriors, and the collapse brought about by the Roman Empire. In the end, the story embroils visitors in the dream of a member of the settlement's elite. Every night he returns to the settlement and remembers fragments of his life such as the first time he saw the walls of the town, the children playing in the street, the courtyard where he learned to fight and the empty city after the downfall. This narrative device makes it possible to use the protagonist's voice to guide visitors around each of the scenes included in this dream-like environment.

For the immersive room it was decided that the 3D effect would be best appreciated if the main motif were to be the constant movement to be seen in the streets and buildings. For the virtual reality experience, in contrast, it was important to establish an exact point at which visitors would appear, and always in places that would encourage them to move around and explore, such as on the corner of a building so that by moving sideways an interior courtyard would become visible, or besides an open door beckoning people to enter. Great attention was paid to the audio for both of these media, with a complex soundtrack perceived three-dimensionally by visitors whereby the sources of the different sounds can be located in the surrounding scene, the overall sensation being one of perfect and total immersion.

5. Public response

People have responded enthusiastically to both the individual VR and the group immersive room experiences. With regard to the latter, the impact created by some of the scenes, such as the flight over the Iberian town, and the appearance of objects which visitors can later see in the museum display cabinets, demonstrates that this medium is highly effective. For most people this was the very first time that they had used a VR headset, and the reaction to it was incredible. The first thing to note is the fact that it is a medium suited to all ages, being warmly received by children of twelve years of age, to people in their 90s. It is particularly interesting to note the impact it had on older people. Their experience was particularly vivid and emotional. Furthermore, it was a particularly striking discovery for people with restricted mobility. People confined to wheelchairs, for example, experienced a sensation of freedom of movement that was a revelatory experience for some of them, and this has led to us establishing contact with hospitals specializing in rehabilitation to offer such a service to them.

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