Digital surveying

Thanks to the use of non-invasive techniques and remote sensing in a 19th century building, it was possible to demonstrate that said building is a lost part of the Cáceres wall. This wall was believed to maintain the straight line from a known section, but remote sensing makes it clear that at that point the wall makes a break creating a door of which there was no record. Once this premise was confirmed, an ideal reconstruction hypothesis was developed. For this, the work base was taken on the data collected in an exhaustive data collection process, which launched millions of control points and facilitated in theorizing the original state of this lost section. The HBIM methodology greatly facilitated the process, and will allow for possible modifications with an IFC file as advances are made in that area. Finally, the research proposes an architectural project path that takes into account the data obtained remotely, and that achieves the inclusion of this part of the city in cultural interest and, of course, in a protected and cataloged area.

Livorno, in Tuscany represent the main harbor in this part of the Mediterranean coast. With the establishment of the Free Port, in 1676, the arrival of merchants was favored and the demand for warehouses, capable of accumulating goods in the port of transit, increased considerably. For this reason, the system of fortifications was strengthened towards the sea and modernized by Cosimo III. Along with the modifications of the fortifications of the city, the project of a fort at the extremity of the “Molo di Cosimo” was also entrusted to the Grand-Ducal Architect Pier Maria Baldi in 1684. General Alessandro Dal Borro chose the design model and supervised the construction of the fort, which began in 1688 at the tip of the “Molo Cosimo”. The complex could control both the interior of the port and the open sea. The main function assigned by the authorities to this fortress was to bomb ships that intended to violate the neutrality declared in 1646, becoming, in fact, a peaceful observatory that, even in moments of tension, did not fire a shot to attack. Thus, it was equipped with an extended system of tunnels to allow the safe movement of people, ammunitions and cannons in case of a battle. This war machine is now in a quite complex state of abandon with a serious loss of architectural identity, mined by fragmented architectures growth all around the fortifications and with the galleries filled with the ruins remained around after the World War II bombings. In 2017-2018 for the first time after 70 years, the Port Authority of Livorno, operated the full removal of the ruins fitted in the galleries, allowing a complete digital survey of an architecture finally brought back to have a chance or revitalization. In this paper it will be presented the products of this research, showing the accurate and unedited representation of this long-lost fortress.

Istanbul has an extended story to tell, but sometimes the idea of its urban development seems frozen to some specific passages in time, while, on the contrary, such an urban context is subject to a continuous transformation of its tissue, changing functions, behaviours, rules. The built heritage keeps on being exploited and reused, dragged in the contemporary age with alterations, superfetation demolitions. The actions of the people living and using the neighbourhoods sometimes cause the decay of a structure into a poorly used facility, sometimes it acts changing decay into opportunity, keeping somehow alive the place. In the case of the waterfront of the Beyoglu quarter, the use of 3D laser scanner for urban documentation allowed to capture a 3D model usable for investigations and understanding, working as a first central node in the interpretation of the complexity of a difficult mix of commercial activities, past abandoned industrial blocks and heritage. This research describes the main passages and activities aimed at the definition of possible guidelines for urban regeneration while preserving intangible heritage values, recognized as a richness for the community itself.

The territory of Verona, due to its geographical position and its topographical, geological and economic
characteristics, since the earliest times heldan eminent role in military history. From the Roman times up to
the formation of the most recent "Quadrilateral" of Austrian origin, the Verona defensive system played a
major role in the development of defensive technologies and strategies for the urban qualification of military
architecture.
With more than 10 km of wall extension and the occupation of 100 hectares of land with ditches,
embankments and towers, the defensive system has been perceived by the city throughout the last century as
a bulky "wreck". The great magistral city walls which lost its defensive function hindered the ordered and
modern development of the city, today are one of the strong points of the UNESCO nomination of the City
of Verona that "represents, in an exceptional way, the concept of a fortified city during the different
significant eras of the history of Europe". The multi-year research project governed by an agreement between
the City of Verona and the Department of Civil Engineering and Architecture of the University of Pavia,
concerns the documentation of the entire fortified perimeter and the development of a 3D survey for the
construction of a digital database connected to the filing of the main elements constituting the defense system.
The aim is the documentation of the building's masonry and the elaboration of drawings from which to
acquire information useful for the protection and conservation of artifacts, as well as models and digital
reconstructions useful for the enhancement and development of these large urban containers. At the moment,
the surveys of the main urban gates have been carried out, different methods of data acquisition on the wall
layout have been tested for the development of the census system and 3D models have been elaborated on
some Sanmicheli’s projects, for the development of hypothesis of historical reconstruction of the different
phases involved in the development of the defense system.

The Opera Punta Rossa fortification was built at the end of XIX century (1887) on the South of Caprera island (North Sardinia), when returned to thinking of La Maddalena archipelago as a strategic military centre, no longer determining in relation to the only French border, but to the much larger chessboard of the Western Mediterranean. It is of singular interest not only for the functional parameters but, above all, for its imposing appearance with wide dimensions, and other many interesting technical-architectural aspects: laying modes of wall structural elements (i.e., for access portals, intrados of vaults, moldings, architraves, jambs, thresholds, cantons), use and working technics of the granite stone expertly molded for the thick masonry, characterized by the presence of loopholes and continuous modulation of materials with moldings and worked stone ashlars to highlight the wall surface. The geomaterials used are local rocks outcropping in the area of Opera Punta Rossa, belonging to the Paleozoic granitic pluton of Gallura and to the associated filonean bodies (Upper Permian - Carboniferous, between about 320 and 270 million years ago). In the fortification have been mainly used the "granite" rocks (substantially biotitic granites and granodiorites) and subordinately also the filonean rocks (especially for irregular ashlars) with variable colours and dacitic-rhyodacitic composition. Generally, the cornices and the openings were made with the lighter greyish granite facies. The stone elements were laid in place using lime or hydraulic / pozzolanic based mortars. Conglomerates and cement-based concretes were used for throwing pitches in even thicker castings. In some subsequent renovations, bricks were also used. The photographic and digital relief was carried out using laser scanner methodologies, which has allowed to define the conservation status of the Opera Punta Rossa complex, producing a 3D model of the current state of building.

The topic presented in this paper is part of a wider research network about the Elban fortification system that last year has produced two works discussed during the Italian edition of the FortMED 2016. The research proposed this year has the will to give the actual state of remains of the Fortress of Giove near Rio nell'Elba (Livorno, Italy). The fortress was built in 1459 from the Appiani family, at that time authority of the Elba Island. Initially it was rectangular shaped with a scarped wall and a dry moat all around its perimeter and a fortified tower with the entrance on the North façade. The fortress was destroyed first by the Ottoman pirate Dragut in 1533 and decisively from the Spanish governor of Porto Azzurro, Mouroy de Pinel. The aim of the digital survey, operated with a 3D Laser Scanner and a professional photographic equipment, is to have a complete coverage of the entire structure, without forgiving the masonry texture, useful to bring hypothesis about its original shape and eventual architectural changes. Also this study will contributed to complete the panoramic view of the Elban fortifications started in 2016 for initiative of the Architecture Department of the Florence University.

Il Battistero di Biella costituisce un esempio in Italia di battistero quadriconco. La sua costruzione è avvenuta a partire dal IX secolo, su un sepolcreto tardo-romano. In esso è possibile riconoscere gli elementi tipici del Romanico. L’impianto a base quadrangolare si amplia in quattro corpi semicilindrici, separati dai pilastri angolari che creano la base per sostenere il tiburio. Il suo assetto architettonico e la sua scala lo rendono un elemento di forte suggestione. In tal senso, il rilievo e la documentazione del battistero - attuati con tecnologie speditive come la fotogrammetria digitale finalizzata a produrre modelli tridimensionali di alta qualità - permettono di creare modelli digitali di studio confrontabili con altri testimoni architettonici.

The Baptistery of Biella is an example in Italy of a quadriconco baptistery. It has been built from the IX century, on a late-Roman burial ground. In this baptistery it is possible to identify some typical elements of the Romanesque Architecture. The quadrangular plant has got four lateral semi-circular rooms, divided by angle pillars aimed at supporting the lantern. With its architectural structure and its scale it is an element of strong suggestion. For this, the survey and the documentation of the baptistery - made by speed technologies like digital photogrammetry aimed to the production of high quality 3D models - let us to create digital study models comparable with other architectural witnesses.

In the XX century, after being forgotten for centuries, a series of archaeological excavations have brought to light the settlement, named “Montecastrese”, a system of Medieval fortifications organized on the top of a hill near the town of Camaiore, on the Tirreno sea, placed at the borders of the Lucca Province. The archaeologists brought back to light the traces of the fortress and of the village, exploring the monumental ruins of the northern tower, still in place and tumbled down in two main large parts. In the first half of the XIII century, the castle of Montecastrese was conquered and destroyed by the army of Lucca. At the time of its major development the small fortress was organized around two main towers, with walls and various houses. A quite extended village was placed on the southern side of the hill. In 2015 a new survey campaign brought contemporary technologies between these ruins. The municipality of Camaiore commissioned a complete digital survey to the Dipartimento di Architettura in Florence. The general survey plan has seen the use of aerial photogrammetric survey, 3D laser scanner survey and terrestrial photogrammetry. The large amount and the high quality of data allowed the definition of a perfect base to start studying and investigate the site to operate a digital reconstruction. The use of 3D modeling of all the lost parts, from the houses to the defense walls, to the system of towers was one of the focal point in this work, using the modeling process from the survey and supporting the reconstruction hypothesis with previous archaeological data, while matching the missing parts with similar architectures and the needs of the medieval defense/attack technics. For the northern tower a specific operation based on the use of 3D printed models was brought on to bring to an end the debate about the sequence of the fall of the tower, quite important to the digital reconstruction of this building, the direct manipulation of a scaled model turned out to be a fundamental step for the completion of this part of the research.

Relevance for the conference:
We bring a complete data processing, from digital survey to digital reconstruction, to the integration with the state of knowledge about the site and create a “final” version of the whole settlement for research and dissemination purposes.

Relevance for the session:
A case study were the authors themselves have followed all the operations, from the survey, to the data processing to a very specific use of 3D printing to allow reconstruction hypothesis.

Innovation:
Specific use of 3D printing for understanding and reconstruction, a selection of results are aimed to public presentation in the local museum rooms (using graphic and 3D physical models).

References:
GATTIGLIA, G. / ANICHINI, F. (2009): La Versilia nel Medioevo. Ricerche archeologiche in un’area buia della Toscana settentrionale, Atti del V Congresso Nazionale di Archeologia Medievale Foggia-Manfredonia 30.09-03.10 2009, Firenze 2009
GATTIGLIA, G. / TARANTINO, G. (2013):…loco ubi dicitur castello. Montecastrese e l’incastellamento in Versilia, in Archeologia Medievale XL

Highlights: The "mosquito fleet" has a specific page in the WWI naval wars. Based on a specific ship, it is missing detailed documentation, the survey of the last one can highlight that episode. The digital survey of the Eothen has a strategy aimed to allow the full documentation of the shipwreck in a very difficult environment, managing floods, mud, vegetation and reflections. The drawings and the 3D model, accessible from a free platform allow complete access to this ruined ship, a contribution to knowledge and a base for possible intervention hypothesis. Abstract: The research presented here puts together different direct and/or physical operations all aimed to enhance the knowledge and produce advanced dissemination of the very last ship from the "Mosquitos' Fleet" which operated during the World War I and in some operations even during the World War II. The exploration of the valuable remains along the Thames River in London, the intervention with archaeology strategy, the use of digital survey procedures, the investigation of the references about the fleet, the digital modelling and drawing and the final online sharing of the 3D model, brought together to a specific digital heritage creation of an element with a high risk of getting lost. An international team worked together on the poor shipwreck of the Eothen (the last name assigned to this ship by its last owner). The intervention was operated in very odd operative conditions, with the hull invaded by the mud, the very wet environment and the daily flood of the area, such a mix of difficult conditions were a special challenge for the survey operations, which were optimized and accurately planned to allow the best and efficient result in terms of coverage and level of details. The following post-processing aimed to the production of a classic set of 2D drawings and an interactive 3D model, accessible in a real-time visualization from the sketchfab.com platform creates an excellent base for a possible following restoration/musealisation intervention, or, at least, allow digital preservation of a rich dataset of the remains of this interesting piece from the naval history of the first half of the 20 th century. Resumen: La investigación que aquí se muestra reúne diferentes operaciones directas y/o físicas, todas orientadas a mejorar el conocimiento y producir una puesta en valor del último barco de la "Flota de Mosquitos" que operó durante la Primera Guerra Mundial y en algunas operaciones incluso durante la Segunda Guerra Mundial. Presentamos la exploración de los valiosos restos a lo largo del río Támesis en Londres, la intervención con estrategia arqueológica, el uso de procedimientos de levantamiento digital, la investigación de las referencias sobre la embarcación, el modelado y dibujo digital, y el intercambio final en línea del modelo 3D, reunidos en una aportación de patrimonio digital específico de un elemento con alto riesgo de perderse. Un equipo internacional , trabajaron juntos en el naufragio del Eothen (nombre asignado a este barco por su último propietario). La toma de datos se realizó en condiciones operativas muy complejas, con el casco invadido por el limo del rio, el entorno muy húmedo y la inundación diaria de la zona; esta mezcla de condiciones difíciles fueron un desafío especial para llevar a cabo las operaciones de levantamiento, las cuales fueron optimizadas con el objetivo de obtener el mejor y más eficiente resultado en términos de cobertura y nivel de detalle. El siguiente posprocesamiento estuvo dirigido a la obtención de un conjunto clásico de dibujos 2D, así como de un modelo 3D interactivo, accesible en una visualización en tiempo real desde la plataforma Sketchfab.com. Así se ha creado una base excelente para una posible intervención posterior de restauración/musealización, o, al menos, para obtener la RODRÍGUEZ-NAVARRO et al., 2021 Virtual Archaeology Review, 12(25): In Press, 2021 2 preservación digital de un rico conjunto de datos de los restos de esta interesante pieza de la historia naval, de la primera mitad del siglo XX.

Elba territory presents a dense network of forts and outposts created by the various dynasties and conquerors that ruled the Island through the centuries. This defensive apparatus was connected by ancient paths, routes and visual systems, as it is possible to notice from the landscape, showing the various watch towers located on hills. The visibility among these archaeological evidences can still be observed as no changes has been made to their context. The most important fortresses are: Giove Fort, Volterraio Castle and St. Giovanni Tower, which are located on strategic areas to control the whole perimeter of the Island and of the Mediterranean Sea. They represent a potential visual line on heights, which all coastal fortification systems referred to. The use of digital tools, 3d laser scanner technologies and photogrammetric survey, make possible to understand the evolution of this military apparatus and the communication method between the Giove Fort and the other main outposts. The acquired data aim to a better knowledge of the Giove Fort and the role it played in the past. The final documentation can provide an improvement of the bibliography, promoting a kind of virtual tourism. By the use of multimedia applications and web sites, visitors can interact with digital and physical 3D-models of the archaeological complex, avoiding accessibility obstacles. The paper proposed here will show the description and the analysis of this documentation and dissemination project.

This contribution offers the initial results of an ongoing multidisciplinary project aimed at exploring digital approaches to overcoming the complexities associated with certain archaeological monuments, such as the Hypogeum of Calaforno, one of the most interesting prehistoric monuments in Sicily. It is a unique sample of rock-cut architecture in terms of size and architectural features, in comparison with the Sicilian territory and the entire Mediterranean context. In addition to the usually rock-cut architecture characteristics, as the narrow spaces and the lack of light, the hypogeum also presents some practical problems due to the serpentine route of the rooms and the presence of water in some spaces. This case study highlights the need to pursue the development of digital products which have a clearly scientific value and can also improve the dissemination aspects. The paper also shows the development and experimentation of workflows to obtain viable 3D digital twin models through the use of low-cost techniques for the photogrammetric surveying of archaeological sites characterized by the presence of narrow and complex spaces. Thanks to the comparison with the laser scanner point cloud of a previous survey, it was possible to verify the accuracy of the photogrammetric model. This has been obtained through the use of the action cam GoPro Black Hero 6. This cam proved to be a highly useful instrument, with lenses offering fields of view somewhere between those of fisheye lenses and of traditional lenses. The aim of this work is the communication of cultural content to the public through immersive virtual experiences that can enhance real visits to stimulate public interest and improve understanding of the monument with the help of unique reception and observation structures based on innovative enabling technologies. The construction system is designed to integrate analogue and digital apparatus and allow the creation of privileged observation points to experience 3D reconstructions of the site.

In the deep core of Turkey, in Cappadocia, the Meryem Ana church in Göreme, is a meaningful
place, rich of suggestions, it is carved in an emerging peak, it faces on the “valley of the swords” 25 meters
high over the area where the valley becomes narrow. It’s a small church, but enriched with wonderful mural
paints, showing the stories from the Bible about the mother of Christ Mary. The main problem of this church
is the large crack dividing in two parts the whole structure, threatening almost the whole church. Other parts
of the cave system are already gone lost and the access is done passing through the remains of tunnels and
small openings. The water passing by the large crack has partially damaged a large area of the mural paints
cancelling their colours. So while our mission was visiting the area during September 2012, it came out
clearly that there was no time to lose and our group has operated the 3D laser scanner survey of this
monument, finding the needed time in an already very dense agenda. The survey work was planned in three
main solutions: photographic survey, laser scanner survey, panoramic photos survey. The results are quite
impressive, because they allow reading quite clearly how dramatic is the condition of the crack and to read
the extension of this imminent disaster. But at the same time the digital survey is also the right base to start
projecting possible interventions on the church and its mural paintings. The possibility to carry into the whole
work in a very short time according to the possibilities of the digital tools, showed how a correct
documentation can be done also in emergency situations allowing to preserve the status of a monument
reducing the risk of its total loss.

For years we have approached the architectural heritage through the traditional drawings, based on data collection taken from sketches and point to point measurements; however, today we can rely on different systems that make necessary to consider not only the phases of the elevation but the methodology to follow, constituting in itself a study that needs to be addressed from the knowledge of advanced data collection techniques. Thus we must analyze what is special about the work and what are our research needs, which will give rise to a list of products to be obtained and will result in a number of plans to scale, photogrammetries, 3D models, pictures and videos. Only then will we obtain the appropriate methodology which may include traditional direct surveys, photogrammetric surveys (2D correction, 3D restitution), 3D laser scans, drones, photographs, spherical panoramic photographs, video, etc.
In the present communication we describe the process followed in determining the methodology that is being carried out in the elevation of a building corpus that presents special characteristics due to the diversity of geographical locations and the dimensions and materials used, as well as its conservation status.

Documenting large architectures with an accurate survey has recently become possible even with a limited budget. Digital survey tools based on both active and passive solutions, offers today versatile opportunities for the architectural documentation, regardless of the building's dimension. This paper presents the poster, prepared for the CHNT conference, with an extract of Terrestrial and Aerial Photogrammetry and Terrestrial Lasergrammetry. This was used by academics in the context of the Kyrenia Castle in the Cyprus Island, a large medieval fortification organized in an almost square planimetry with a side of about 150 meters and walls height up to about 30 meters, gathering the occasion of a specific workshop (activated for one week in May 2018) and producing the first (partial) digital model of this large built heritage. Following the protocols and best practice in digital documentation of this kind of architectures-the coordinator group of the workshop in synergy with the management unit of the museum hosted in the castle-has brought on an articulated experience moving from the morphology of the castle, to its stratigraphy, to its exhibition aspects, to its restoration issues, to the production of multimedia contents for technical and/or general public access. In that poster it was presented the structure of the workshop, the structure of the survey, the interactions and integrations between different surveys, the system of tools, and the results coming out at first, from the on-field operations brought on by the students participating to the workshop and the following processing operated by technical expert operators; going on to the development of common digital bases to evolve the way of approach to these monumental structures. To present the complete workflow with samples the poster was enriched with QR-Code links to online resources has been made to be a useful base for sharing and discussing the whole set of activities completed on this subject.

In the past century, at the end of the fifties, the project of the Aswan High Dam, put the monuments of Nubia in danger. UNESCO promoted the “Nubian Campaign” to involve western countries in the salvage of the Abu Simbel Temples. The survey of the area, essential for the operations, was made by the Institut Géographique National Français (from 1956 to 1963), using innovative – for those times – technologies like photogrammetry.

In the XXth century, a series of archaeological excavations brought to light the settlement named " Montecastrese, " a system of Medieval fortifications located on the top of a hill near the town of Camaiore, on the Tyrrhenian coast of Italy. The site had been abandoned for centuries before the archaeologists brought to light traces of the fortress and of the village, exploring the monumental ruins of the northern tower, still in place but consisting of ruins in two main areas. In the first half of the XIIIth century, the castle of Montecastrese was conquered and destroyed by the army of Lucca. At the time of its major development, the small fortress was organized around two main towers, with walls and houses. A quite extensive village was located on the southern side of the hill. In 2015, the municipality of Camaiore commissioned the Dipartimento di Architettura in Florence to make a complete digital survey of the area. The general survey plan was made using an aerial photogrammetric survey, a 3D laser scanner survey and terrestrial photogrammetry. The 3D modeling of all the lost parts, from the houses, to the defense walls, to the system of towers, was one of the focal points in this work, which used the modeling process from the survey and supported the reconstruction hypothesis with previous archaeological data. At the same time we matched the missing parts with similar architecture and took into account the defensive and offensive features of the medieval fortress. For the northern tower, a specific operation based on the use of 3D printed models was employed in order to settle the debate about the sequence of the tower's collapse. This was quite important to the digital reconstruction of the building, and the direct manipulation of a scaled model turned out to be a fundamental step for the completion of this part of the research.

The effective use of technology offers numerous benefits in protecting cultural heritage. With the proper implementation of these tools, the management and conservation of artifacts and knowledge are better attained.

The Handbook of Research on Emerging Technologies for Digital Preservation and Information Modeling is an authoritative resource for the latest research on the application of current innovations in the fields of architecture and archaeology to promote the conservation of cultural heritage. Highlighting a range of real-world applications and digital tools, this book is ideally designed for upper-level students, professionals, researchers, and academics interested in the preservation of cultures.

The fortified settlement of Bivignano (Arezzo, Italy) is a part of a large system of castles developed between the eleventh and twelfth centuries in a minor valley of the Cerfone river, an affluent of the Tiber river. Founded by the family of the Count of Bivignano, the castle is a part of the noble residence (a “casa- torre” typology with a plan dimension of 10.25 by 7.50 meters, of which 9.30 meters are still intact) and with the adjacent church of Santa Maria (rebuilt in the seventeenth century on the original early medieval chapel). The rest of the buildings consist of housing and service areas, which have been in use until the mid- seventies. Today the castle is in a deep state of abandonment also due to the continuous looting that deprives it of the architectural elements that are easily re-usable elsewhere, which accelerates the
processes of decay. The research group DM_SHS at DiDA (Dipartimento di Architettura dell’Università degli Studi di Firenze) has recently initiated a digital survey campaign aimed to the production of 3D models, useful not only to provide documentary evidence of the entire castle and to support stratigraphic, metrologic, and structural/diagnostic analysis, but also to try out advanced texturing procedures, made available by the use of computer graphics (such as baking and UV parameterization), capable to correlate the results of such analysis to the models themselves; this allows a more appropriate reading of the information and facilitates the dissemination of the results also through the web. The paper will therefore be able to assess the progress of scientific research in the particular field that gathers together digital survey, 3D modeling and computer graphics for furthering the knowledge, enhancement and dissemination of the cultural heritage.

In the field of documentation of cultural heritage, the employment of surveying instruments and methods and graphic representation that use digital technology has become a consolidated praxis in the past decades. The literature of such issues tends to show, with few exceptions, the potential (often not fully expressed) of the latest hardware and software, throughout surveying experiences, some more intriguing than others (from a figurative point of view), without really indulging on the true problems behind their overall usage: from the very first data-acquisition to the final graphic panels. In truth, the procedures for digital survey are relatively new and not unanimously shared by the scientific community, and the central role taken by 3D digital models in such a processes is often mystified. Maquettes with apparent colour textures, achieved throughout the integrated use of image-based techniques (digital photogrammetry) and range-based tools (laser scanner), do not always lead to a correct understanding and interpretation of the architectural artefacts, hence impedes to proficiently describe them throughout the codes of representation. The contribution aims to provide, with the chosen examples, some indications in this apparent paradox, with special emphasis on the limitations of nowadays technologies and the complications that could arise due to a-critical construction of digital models.

The basilica of St. Silvestro, at the catacombs of Priscilla in Rome is a recent construction, it was
built in the early XX Century, but it was constructed over the foundations of a structure developed in different
times during the Late Antiquity. It is now at the end of a meaningful restoration. The South-East part of the
original building was conceived as a space for burials. Currently this area is used as storage for the
archaeological materials found during the excavations of the past century. The new museum of the
sculptures will contain 405 pieces of sarcophagi dated between the beginning of the III Century A.D. and the
first half of the IV Century A.D. One of the most important pieces in this collection is a well preserved marble
sarcophagus, dated around the III Century A.D., engraved with scenes from everyday life, agriculture and
sheep-herding. This piece is the object of this paper, quite a challenge for a digital survey, because of the
complex characteristics features of the sculptures and it’s fine details. And last but not least due to the
difficulties linked to the light subsurface dispersion of the marble. For these reasons the survey was based
on the Structure from Motion process, using a digital SLR camera and a specific SfM software. The main
advantages of this choice are the reduction of the instrument costs and their practical management: all was
done with a good quality camera, a tripod and some studio lights, while a single, middle price, software was
used to produce the final digital 3D model. The final results, edited and optimized in different solutions for
multimedia presentation and prototyping were soon ready for further use, like the implementation into a
multimedia database of the details. (under development).

Il battistero di Biella costituisce uno dei pochi esempi rimasti in Italia di battistero con impianto quadriconco. La sua costruzione è avvenuta in varie fasi a partire dal IX secolo, andando a stabilire le proprie fondazioni su di un sepolcreto tardo-romano, tuttavia l’impostazione quadriconca è indubbiamente da attribuire ad una scelta progettuale originale. Si tratta di un edificio in cui è possibile riconoscere gli elementi tipici del romanico, con una massa muraria omogenea e costituita da ciottoli di pietra commisti e intervallati da parti in laterizio. Questo battistero è stato espressamente pensato per celebrare il battesimo secondo il rito ambrosiano e, come è naturale per questo tipo di realizzazione, gli elementi formali e la struttura architettonica si legano ad aspetti simbolici e necessità del rito. L’impianto a base quadrangolare si amplia in quattro corpi semi-cilindrici, separati dai quattro pilastri angolari che creano la base necessaria a sostenere il tiburio che estende la geometria dello spazio in una pianta ottagonale. Alcuni elementi oggi possono introdurre delle alterazioni sensibili rispetto all’impianto originale, come la cripta a croce greca realizzata nel 1791 con uno scavo al di sotto del piano di calpestio del battistero, oppure come l’introduzione di una lanterna con bifore sui quattro lati posizionata a chiudere l’oculo della copertura; la presenza di elementi di spoglio ha portato in passato a ipotizzare una derivazione dell’edificio da una costruzione precedente e più antica. Il suo assetto architettonico, la sua particolare scala e proporzione, lo rendono un elemento di forte suggestione, capace di trasmettere sia il rapporto tra arte romanica e forme precedenti, sia la persistenza di soluzioni espressive che proseguono tra il passato romano e le formule rinnovate del romanico. In tal senso, il rilievo e la documentazione del battistero di Biella -attuati con tecnologie speditive e contemporanee come la fotogrammetria digitale finalizzata a produrre modelli tridimensionali di alta qualità- permettono di creare modelli tridimensionali digitali di studio e analisi facilmente confrontabili con altri testimoni architettonici. Possono quindi costituire un importante riferimento i ruderi di una delle fasi “evolutive” del battistero di Lucca, rilevati con tecnologia 3D laser scanner e trattati al fine di meglio comprendere la forma originale di questo edificio, ma anche i ninfei romani, costituiti da quattro vasche semicircolari e potenzialmente in stretta relazioni con il senso dell’acqua fluens e della soluzione architettonica atta a gestirla e contenerla. Punto importante di reciproco scambio tra i modelli diventa quindi il rapporto di dimensionamento tra spessori murari e alzati, la gestione dello spazio, la soluzione di copertura e le suggestioni create da queste architetture. Appropriate tecniche di rilievo digitale e conseguenti trattamento del dato permettono di ottenere soluzioni di confronto e comparazione capaci a concretare e rendere più chiaro il rapporto tra idee, suggestioni e evidenze oggettive e verificarle al di fuori della scala, della condizione dell’edificio, della sua posizione architettonica. Il tutto al fine di riscoprire in forma contemporanea e di facile disseminazione, una particolare tipologia di edificio che ha mediato la formula prima orientale e poi romana del ninfeo per trasformarla in un edificio massivo e concreto capace di creare quelle condizioni di riconoscibilità e ripetibilità della struttura architettonica che fortemente hanno contribuito alla costituzione di un “paesaggio” romanico nella propria epoca e che a tutt'oggi costituiscono uno spunto ed uno stimolo di grande suggestione per il ricercatore e lo studioso.