Francesco Fassi

Politecnico di Milano | Polimi · Department of Building and Environment Sciences and Technology BEST

Although the field of geomatics has seen multiple technological advances in recent years which enabled new applications and simplified the consolidated ones, some tasks remain challenging, inefficient, and time- and cost-consuming. This is the case of accurate tridimensional surveys of narrow spaces. Static laser scanning is an accurate and reliabl...

3D reality capturing has demonstrated increased efficiency and consistently accurate outcomes in architectural digitisation. Nevertheless, despite advancements in data collecting, 3D reality capturing still lacks full automation, especially in the post-processing and modelling phase. Artificial intelligence (AI) has been a significant focus, especi...

Although the field of geomatics has seen multiple technological advances in the recent years which enabled new applications and simplified the consolidated ones, some tasks remain challenging, inefficient, and time- and cost-consuming. This is the case of accurate tridimensional surveys of narrow spaces. Static laser scanning is an accurate and rel...

Image classification and object detection techniques have been widely discussed and developed in recent years; they are the basis of various prosperous applications, for example, real-time mapping. Promising as it is, the practical test in the cultural heritage field encountered multiple problems. In this paper, the authors attempt to share the res...

The advent of mobile mapping systems (MMSs) and computer vision algorithms has enriched a wide range of navigation and mapping tasks such as localisation, 3D motion estimation and 3D mapping. This study focuses on Visual Simultaneous Localisation and Mapping (V-SLAM) in the context of two in-houses MMSs: Ant3D, a patented five-fisheye multi-camera...

Digital technology provides methods to record and preserve cultural heritage, support conservation and restoration efforts, and share our collective past with a worldwide audience. Between 2011 and 2017, the 3D Survey Group from Politecnico di Milano operated an annual workshop in the medieval village of Ghesc in which photogrammetry and laser-scan...

Photogrammetric applications nowadays envisage the use of more and more low-cost cameras such as those equipped on commercial UAV platforms. Typically, these low-grade cameras suffer from extreme radial distortion and strong vignetting among other defects. This, initiated a trend among the low-cost cameras’ manufacturers to try to hide the camera d...

Multi-camera devices are increasingly popular in various metrological applications, including cultural heritage digitalisation, where these devices are adopted as low-cost alternatives to more traditional methods or mobile mapping systems. They can be of two types: panoramic and non-panoramic configurations, with the former usually more compact and...

The presented research resulted from an unusual educational experience that brought lecturers in surveying and three-dimensional digitalization with lecturers in heritage conservation. The courses explore the possibility of utilizing digital reality-based models to better analyze, organize, and create reuse activities using virtual reality and a ho...

Point clouds are nowadays a standard format of three-dimensional data. Various survey techniques are available, differing in characteristics, mode of use, and target applications, nevertheless producing point clouds that are similar, comparable, and combinable. According to recent literature, combining data from multiple sensors is an established p...

This paper describes the digitization test of Fonte Giuturna (Giuturna spring) in the Roman Forum area, from survey to data management through the in-use monitoring system, the WebApp SyPEAH of the Parco Archeologico del Colosseo. The location of Giuturna Spring, characterized by the presence of heterogeneous archaeological remains from different a...

In cultural heritage, three-dimensional documentation of historic buildings is fundamental for conservation and valorisation projects. In recent years, the consolidated tools and methods: Terrestrial Laser Scanning (TLS) and close-range photogrammetry, have been joined by portable Mobile Mapping Systems (MMSs), which can offer significant advantage...

This paper presents an investigation into the characterization of historical gardens by comparing two 3D survey methodologies. In this context, approaches employing terrestrial laser scanning are considered the most accurate, while Mobile Mapping Systems (MMSs) are considered promising due to their extreme productivity. Less common is the use of cl...

Fixed-wing Unmanned Aerial Vehicles (UAV) and wearable or portable Mobile Mapping Systems (MMS) are two widely used platforms for point cloud acquisition with Light Detection And Ranging (LiDAR) sensors. The two platforms acquire from distant viewpoints and produce complementary point clouds, one describing predominantly horizontal surfaces and the...

In the field of geomatics, the development of 3D surveying techniques that can produce dense point clouds and high-resolution three-dimensional models has opened the possibility of using these techniques to generate digital replicas of a given asset to be used in contexts of cultural promotion or entertainment.These non-traditional applications hav...

In recent years, the investigation and 3D documentation of architectural heritage has made an efficient digitalization process possible and allowed for artificial intelligence post-processing on point clouds. This article investigates the multilevel multiresolution methodology using machine learning classification algorithms on three point-cloud pr...

As a result of the development of Artificial Intelligence (AI) techniques, in recent years, machine learning (ML) and deep learning (DL) approaches have been widely used to semantically enrich 3D architectural cultural heritage (ACH) point clouds. While existing approaches for analyzing and interpreting point clouds continue to improve, the general...

La ricerca in corso, sostenuta dal Progetto Interreg Italia-Svizzera A.M.AL.PI.18, riguarda l'elaborazione e gestione dei dati provenienti da attività di indagine finalizzate a produrre ipotesi e modelli utili alla ricostruzione delle cause, modalità e degli effetti di eventi franosi.

Indoor Mobile Mapping Systems (IMMS) are attracting growing attention, especially when LiDAR sensors are considered, thanks to the possibility to obtain wide range and complete data in those areas where GNSS signal is not available. However, the drift error that accumulates during the acquisition is often inadequate in the absence of quality constr...

Indoor Mobile Mapping Systems (IMMS) are attracting growing attention, especially when LiDAR sensors are considered, thanks to the possibility to obtain wide range and complete data in those areas where GNSS signal is not available. However, the drift error that accumulates during the acquisition is often inadequate in the absence of quality constr...

The paper outlines the first steps of a research project focused on the digitalization of underground tunnels for the mining industry. The aim is to solve the problem of rapidly, semi-automatically, efficiently, and reliably digitizing complex and meandering tunnels. A handheld multi-camera photogrammetric tool is used for the survey phase, which a...

Mixed reality provides on-the-spot and real-time data access capabilities by making virtual models and information more intuitive and accessible. Furthermore, allowing the operator to perceive 3D as holograms would allow for a more natural and straightforward manipulation of the perceived 3D content by permitting the augmentation of real objects wi...

Recent years have seen the investigation and 3D documentation of architectural heritage becoming more accessible. The digitalization process could be more efficient when artificial intelligence is used in processing point cloud models. This article investigates the use of machine learning classification algorithms and a Multi-Level Multi-Resolution...

Indoor Mobile Mapping Systems (IMMSs) technologies are becoming increasingly popular thanks to the possibility of acquiring a massive amount of 3D data in a fast and effective way in those areas where GNSS signal is unavailable, like urban canyons, densely vegetated areas, underground sites and buildings. They offer an efficient way to produce poin...

HoloLens 2 is a state-of-the-art of Mixed Reality device that can augment the natural environment with virtual content in the form of holograms. Spatial mapping is the capability of the device to scan the environment and provide the user with a detailed 3D mesh model representation of its surroundings. The device can place holograms about real-worl...

The task of digitalizing meandering complex spaces in 3D is a challenging one even with the most advanced instrumentation like lightweight terrestrial laser scanner or portable/wearable Mobile Mapping Systems (MMSs). The complexity and extension of architectonic spaces such as staircases, corridors and passages are such that the acquisition time us...

The study presents a part of the operational framework of the “Project for Infrastructure and Strategic Strengthening of the Somali National University”, funded by the Italian Agency for Development Cooperation. The project, coordinated by Politecnico di Milano, aims to reconstruct the Gahayr campus of the Somali National University of Mogadishu, w...

In recent years, Artificial Intelligence (AI) methods for 3D point cloud classification has assumed an essential role in the heritage field. The association of semantic information to 3D representations became a valuable instrument for measurement, analysis, education or maintenance, in particular in the Cultural Heritage (CH) sector. Moreover, the...

The paper presents the first part of a research project concerning the creation of 3D terrain models useful to understand landslide movements. Thus, it illustrates the creation process of a multi-source high-resolution Digital Terrain Model (DTM) in very dense vegetated areas obtained by integrating 3D data coming from three sources, starting from...

Cultural Heritage (CH) 3D digitisation is getting increasing attention and importance. Advanced survey techniques provide as output a 3D point cloud, wholly and accurately describing even the most complex architectural geometry with a priori established accuracy. These 3D point models are generally used as the base for the realisation of 2D technic...

In recent years, a complete 3D mapping of the Cultural Heritage (CH) has become fundamental before every other action could follow. Different survey techniques outputs could be combined in a 3D point cloud, completely describing the geometry of even the most complex object. These data very rich in metric quality can be used to extract 2D technical...

The integration between BIM (Building Information Modeling) and GIS (Geographic Information System) is currently a highly debated research topic. However, the effective integration of the two workflows in a unique information system is still an open research field, especially when dealing with Cultural Heritage (CH).The paper describes an ongoing r...

The recent years saw an extensive use of 3D point cloud data for heritage documentation, valorisation and visualisation. Although rich in metric quality, these 3D data lack structured information such as semantics and hierarchy between parts. In this context, the introduction of point cloud classification methods can play an essential role for bett...

Modern technology offers elaborated and efficient instruments capable of performing extremely accurate surveys of architectural and archaeological remains. However, not all of them can be used everywhere: archaeological missions might be constrained by logistics, environmental and, especially, financial restrictions. This issue is especially felt b...

Archaeology has recently seen a rise in the use of digital tools and new technologies. However, in many cases, innovative tools are used to perform old operations, and their potential is not fully exploited to achieve equally innovative results. Moreover, in the practice of archaeological excavations, the collection of digital data proceeds alongsi...

Information technology touches all the main activities that orbit Cultural Heritage, including management, communication, monitoring and conservation. In particular, advanced digital tools can help the process of preservation, fostering a participatory process connecting diverse experts with various skills and educational backgrounds, and empowerin...

Since 2008, an intense survey has been underway in the Milan Cathedral. The operations, over the years, have been conducted with laser scanner and photogrammetry choosing or integrating the different methodologies according to the environment, the necessary “drawing” to support the different sites’ maintenance operation but always concurrently with...

In the archaeological practice, Digital Terrain Models (DTMs) and Digital Surface Models (DSMs) may be used to represent spatial information about the site by conveying information such as differences in levels, morphology of the terrain and movements of volumes during the excavation. Nowadays DTMs and DSMs can be easily obtained by image-based mat...

This work starts from the request to have a physical high-resolution 3D model of the external, anthropoid coffin of the scribe Butehamon, held at the Museo Egizio, Turin. At the time of writing, a replica of the coffin, based on this survey work, functions as final and focal installation of the temporary exhibition Archeologia Invisibile of the Mus...

Photogrammetry is a survey method that provides good quality results also by using basic photographic equipment and user-friendly, low-cost software. The advantages of the image-based modelling techniques compared with the traditional topographic tools are very significant in emergencies, when the time for the survey is limited and many buildings a...

The paper presents the case study of the complete 3D survey of the area of the Fort of Pietole in Borgo Virgilio using the Leica Pegasus Backpack wearable Mobile Mapping System (MMS). Surveying the site is challenging because of its complex topology on the one hand (with notably narrow passages) and because of the presence of vegetation on the othe...

Nowadays, the researchers in Cultural Heritage fields investigate more and more about advanced conservation strategies that comprehend the possibility to share and use 3D models and structured information related to them. One of the modern method adopted to achieve this goal is to use structured web-platform. These are online systems that can handl...

This study is part of the “Milan Cathedral Survey project”. It is a three years long research project with the aim of surveying the entire cathedral in 3D with different techniques (mainly photogrammetry and laser scanning). The goal is to renew the architectonic drawings (sections elevations and plans) to obtain new updated and certificated measur...

In recent years, special digital cameras called “action camera” or “action cam”, have become popular due to their low price, smallness, lightness, strength and capacity to make videos and photos even in extreme environment surrounding condition. Indeed, these particular cameras have been designed mainly to capture sport actions and work even in cas...

Narrow spaces and passages are not a rare encounter in cultural heritage, the shape and extension of those areas place a serious challenge on any techniques one may choose to survey their 3D geometry. Especially on techniques that make use of stationary instrumentation like terrestrial laser scanning. The ratio between space extension and cross sec...

Since 2011, the 3DSurvey Group of Politecnico di Milano organises an annual summer school programme entitled ‘Laboratory of Places, Ghesc and surroundings, history, survey, evolution’. This activity is patronised by the International Council on Monuments and Sites (ICOMOS) Italia and developed in collaboration with the Canova Association. This is a...

p>This article aims to critically examine the entire methodology of very large scale (1:1) surveying and documentation of mosaic surfaces. The term ‘survey’ should be read in its broadest and most complete and sense, including the phases of measurement and data processing as well as management and use of these data for the purposes of preservation...

Nowadays, the increasing computation power of commercial grade processors has actively led to a vast spreading of image-based reconstruction software as well as its application in different disciplines. As a result, new frontiers regarding the use of photogrammetry in a vast range of investigation activities are being explored. This paper investiga...

In the architectural survey field, there has been the spread of a vast number of automated techniques. However, it is important to underline the gap that exists between the technical specification sheet of a particular instrument and its usability, accuracy and level of automation reachable in real cases scenario, especially speaking about Cultural...

In the recent years, mature technologies for producing high quality virtual 3D replicas of Cultural Heritage (CH) artefacts has grown thanks to the progress of Information Technologies (IT) tools. These methods are an efficient way to present digital models that can be used with several scopes: heritage managing, support to conservation, virtual re...

The Basilica of San Marco in Venice is a well-known masterpiece of World Heritage. It is a real multi-faceted architecture. The management of the church and its construction site is very complicated, and requires an efficient system to collect and manage different kinds of data. The BIM approach appeared to be the most suitable to collect multi-sou...

Accurate 3D city models represent an important source of geospatial information to support various “smart city” applications, such as space management, energy assessment, 3D cartography, noise and pollution mapping as well as disaster management. Even though remarkable progress has been made in recent years, there are still many open issues, especi...

Documentation and preservation of widespread rural heritage are today possible only if you can activate processes of conservation headed by local communities, thereby recognizing the link between the communities and their culture. The cultural heritage places (villages, sites and landscapes) can take different values; action is needed respecting th...

This paper will describe the evolutionary stages that shaped and built, over the time, a robust and solid relationship between ‘indirect survey methods’ and knowledge of the ‘architectural matter’, aiming at producing a conservation project for the built heritage. Collecting architectural data by simply drawing them was considered to be inadequate...

The research illustrated in this article aimed at identifying a good standard methodology to survey very narrow spaces during 3D investigation of Cultural Heritage. It is an important topic in today’s era of BIM modelling applied to Cultural Heritage. Spaces like staircases, corridors and passages are very common in the architectural or archaeologi...

Advanced 3D survey technologies, such as Digital Photogrammetry (imaged based) and Laser Scanner, are nowadays widely used in Cultural Heritage and Archaeological fields. The present paper describes the investigations realized by the Laboratory Hesutech of the Polytechnic of Milan in cooperation with the Superintendence Archaeology Campania in orde...

BIM3DSG system is described here. It is an ad hoc designed BIM system created for Cultural Heritage applications. It proposes some solutions to solve some issues related to the use of BIM in this field. First, it tries to resolve the problem of managing huge, complex, high resolution and heterogeneous 3D models, and then it offers a practical, easy...

BIM3DSG system is described here. It is an ad hoc designed BIM system created for Cultural Heritage applications. It proposes some solutions to solve some issues related to the use of BIM in this field. First, it tries to resolve the problem of managing huge, complex, high resolution and heterogeneous 3D models, and then it offers a practical, easy...

The work presented here is the final step of a multidisciplinary research project conducted on the Milan Cathedral for eight years (2008–2015). Three main topics, consequentially related, will be here addressed: (i) the survey of the structure, meant to update the old drawings; (ii) the construction of an accurate and detailed 3D model to be used t...

Speaking about modelling the Cultural Heritage, nowadays it is no longer enough to build the mute model of a monument, but it has to contain plenty of information inside it, especially when we refer to existing construction. For this reason, the aim of the research is to insert an historical building inside a BIM process, proposing in this way a wo...

Speaking about modelling the Cultural Heritage, nowadays it is no longer enough to build the mute model of a monument, but it has to contain plenty of information inside it, especially when we refer to existing construction. For this reason, the aim of the research is to insert an historical building inside a BIM process, proposing in this way a wo...

Underwater photogrammetry using consumer grade photographic equipment can be feasible for different applications, e.g. archaeology, biology, industrial inspections, etc. The use of a camera underwater can be very different from its terrestrial use due to the optical phenomena involved. The presence of the water and camera pressure housing in front...

Underwater photogrammetry using consumer grade photographic equipment can be feasible for different applications, e.g. archaeology, biology, industrial inspections, etc. The use of a camera underwater can be very different from its terrestrial use due to the optical phenomena involved. The presence of the water and camera pressure housing in front...

The popularity of automatic photogrammetric techniques has promoted many experiments in underwater scenarios leading to quite impressive visual results, even by non-experts. Despite these achievements, a deep understanding of camera and lens behaviors as well as optical phenomena involved in underwater operations is fundamental to better plan field...

Advanced 3D survey technologies, such as Digital Photogrammetry and Laser Scanner, are nowadays widely used in several fields such as Cultural Heritage and Archaeology, allowing to obtain detailed 3D textured models in a fast way for different purposes. These technologies are usually employed to perform single individual surveys but they have rarel...

Geomatics technics and methods are now able to provide a great contribution to the Cultural Heritage (CH) processes, being adaptable to different purposes: management, diagnosis, restoration, protection, study and research, communication, formation and fruition of the Cultural Heritage. This experimentation was done with an eye to encouraging and p...

This paper examines the survey of tall buildings in an emergency context like in the case of post-seismic events. The after-earthquake survey has to guarantee time-savings, high precision and security during the operational stages. The main goal is to optimize the application of methodologies based on acquisition and automatic elaborations of photo...

Precision Farming (PF) Systems can become a win-win approach to guarantee sustainable production of food and energy. As remarked by a recent report of the European Commission, PF can potentially guarantee a high level of production while improving the protection of natural resources. Indeed spatial and temporal variability associated with all aspec...

Precision Farming (PF) Systems can become a win-win approach to guarantee sustainable production of food and energy. As remarked by a recent report of the European Commission, PF can potentially guarantee a high level of production while improving the protection of natural resources. Indeed spatial and temporal variability associated with all aspec...

The paper describes the survey activities of the late Roman archaeological site of Umm al-Dabadib (Egypt). The interesting casestudy can be taken as an example in case of emergency surveys, as this method allows the complete 3D acquisition of a vast and complex area in a very short time and with the aid of simple instruments.

The work is the final part of a multi-year research project on the Milan Cathedral, which focused on the complete survey and threedimensional modeling of the Great Spire (Fassi et al., 2011) and the two altars in the transept. The main purpose of the job was to prepare support data for the maintenance operations involving the cathedral since 2009 a...

In this paper, a Cultural Heritage survey, performed by employing and integrating different type of acquisition technologies (imagebased and active sensor based) is presented. The aim of the survey is to create a 3D multiscale database, therefore, different restitution scales, from the architectural-urban one to a detail one are taken in considerat...

Debris and hyper-concentrated flows are among the most destructive of all water-related disasters and in the recent years have attracted more and more attention from the scientifi c and professional communities and concern from public awareness, due to the increasing frequency with which they occur and the death toll they claim. The study of debris...