1,721,069 research outputs found
The influence of laying patterns on the behaviour of historic stone pavements subjected to horizontal loads
No full textStone pavements are of great importance both for their historical and cultural value and for the most modern ecological and aesthetic requirements appreciated thanks to the use of natural materials of different colours, shapes and sizes which are laid in different patterns. Since stone block pavements are made up of individual elements with irregular side surfaces that interact with each other, an important parameter that must be considered in the design is their structural strength to horizontal stresses mainly due to braking, turning and accelerating vehicles. In this study horizontal load tests were performed on stone pavements built in a wide laboratory test chamber to analyse the load-shifting behaviour for different geometric arrangements. The displacements distribution of the elements was determined by a photogrammetric analysis. The tests have shown that the behaviour of the stone pavements in the horizontal plane is significantly influenced by the laying pattern, both in terms of translations and interaction between the elements. © 2020 Elsevier Lt
A Data-driven Information Modelling Approach for Cultural Heritage
No full textThe documentation of architectural heritage requires interdisciplinary collaboration and advanced information management. Historic Building Information Modelling (HBIM) and Geographic Information Systems (GIS) have enhanced cultural heritage documentation, while eXtended Reality (XR) technologies have improved accessibility and interactive engagement. However, challenges persist in data acquisition, modelling, and classification, limiting the practical implementation of comprehensive heritage information systems.
This study introduces a data-driven information modelling framework optimized for cultural heritage, enabling the integration of 3D survey data and heterogeneous datasets. The framework supports cost-effective reuse of existing datasets by ensuring interoperability through a Broker Database and a Web Programming Interface (Web API). The system facilitates data structure abstraction, data description, geometric management, and spatial analysis, treating diverse datasets as informative layers. Allowing coregistration/ coordinate conversion of 3D models, point clouds, and spherical images in/to a unified spatial reference system, it enhances data accessibility while reducing modelling efforts. The paper illustrates the structure and features of the proposed system, focusing on its brokering role and modular framework. Two case studies demonstrate the framework’s capability and scalability: the Parma (Italy) Cathedral and the Church of Santa Maria della Steccata in Parma (Italy). The system outputs are presented through a Virtual Reality application in Unity, providing dynamic geometry visualization, data querying, and immersive exploration
ACCURACY ASSESSMENT OF 3D MODELS GENERATED FROM GOOGLE STREET VIEW IMAGERY
Full text linkGoogle Street View is a technology implemented in several Google services/applications (e.g. Google Maps, Google Earth) which provides the user, interested in viewing a particular location on the map, with panoramic images (represented in equi-rectangular projection) at street level. Generally, consecutive panoramas are acquired with an average distance of 5–10 m and can be compared to a traditional photogrammetric strip and, thus, processed to reconstruct portion of city at nearly zero cost. Most of the photogrammetric software packages available today implement spherical camera models and can directly process images in equi-rectangular projection. Although many authors provided in the past relevant works that involved the use of Google Street View imagery, mainly for 3D city model reconstruction, very few references can be found about the actual accuracy that can be obtained with such data. The goal of the present work is to present preliminary tests (at time of writing just three case studies has been analysed) about the accuracy and reliability of the 3D models obtained from Google Street View panoramas
UAV Block Geometry Design and Camera Calibration: A Simulation Study
Full text linkAcknowledged guidelines and standards such as those formerly governing project planning in analogue aerial photogrammetry are still missing in UAV photogrammetry. The reasons are many, from a great variety of projects goals to the number of parameters involved: camera features, flight plan design, block control and georeferencing options, Structure from Motion settings, etc. Above all, perhaps, stands camera calibration with the alternative between pre- and on-the-job approaches. In this paper we present a Monte Carlo simulation study where the accuracy estimation of camera parameters and tie points’ ground coordinates is evaluated as a function of various project parameters. A set of UAV (Unmanned Aerial Vehicle) synthetic photogrammetric blocks, built by varying terrain shape, surveyed area shape, block control (ground and aerial), strip type (longitudinal, cross and oblique), image observation and control data precision has been synthetically generated, overall considering 144 combinations in on-the-job self-calibration. Bias in ground coordinates (dome effect) due to inaccurate pre-calibration has also been investigated. Under the test scenario, the accuracy gap between different block configurations can be close to an order of magnitude. Oblique imaging is confirmed as key requisite in flat terrain, while ground control density is not. Aerial control by accurate camera station positions is overall more accurate and efficient than GCP in flat terrain
A RESTORATION ORIENTED HBIM SYSTEM FOR CULTURAL HERITAGE DOCUMENTATION: THE CASE STUDY OF PARMA CATHEDRAL
Full text linkThe need to safeguard and preserve Cultural Heritage (CH) is increasing and especially in Italy, where the amount of historical buildings is considerable, having efficient and standardized processes of CH management and conservation becomes strategic. At the time being, there are no tools capable of fulfilling all the specific functions required by Cultural Heritage documentation and, due to the complexity of historical assets, there are no solution as flexible and customizable as CH specific needs require. Nevertheless, BIM methodology can represent the most effective solution, on condition that proper methodologies, tools and functions are made available. The paper describes an ongoing research on the implementation of a Historical BIM system for the Parma cathedral, aimed at the maintenance, conservation and restoration.
Its main goal was to give a concrete answer to the lack of specific tools required by Cultural Heritage documentation: organized and coordinated storage and management of historical data, easy analysis and query, time management, 3D modelling of irregular shapes, flexibility, user-friendliness, etc.
The paper will describe the project and the implemented methodology, focusing mainly on survey and modelling phases. In describing the methodology, critical issues about the creation of a HBIM will be highlighted, trying to outline a workflow applicable also in other similar contexts
Multi-Camera Rig and Spherical Camera Assessment for Indoor Surveys in Complex Spaces
No full textThis study compares the photogrammetric performance of three multi-camera systems—two spherical cameras (INSTA 360 Pro2 and MG1) and one multi-camera rig (ANT3D)—to evaluate their accuracy and precision in confined environments. These systems are particularly suited for indoor surveys, such as narrow spaces, where traditional methods face limitations. The instruments were tested for the survey of a narrow spiral staircase within Milan Cathedral and the results were analyzed based on different processing strategies, including different relative constraints between sensors, various calibration sets for distortion parameters, interior orientation (IO), and relative orientation (RO), as well as two different ground control solutions. This study also included a repeatability test. The findings showed that, with appropriate ground control, all systems achieved the target accuracy of 1 cm. In partially unconstrained scenarios, the drift errors ranged between 5 and 10 cm. Performance varied depending on the processing pipelines; however, the results suggest that imposing a multi-camera constraint between sensors and estimating both IO and RO parameters during the Bundle Block Adjustment yields the best outcomes. In less stable environments, it might be preferable to pre-calibrate and fix the IO parameters
Integrating 3D survey and open datasets for creating low-cost urban digital twins in VR
No full textThis paper presents a low-cost framework for creating urban digital twins in Virtual Reality (VR) tailored for heritage preservation and smart city applications. The increasing demand for urban digital twins necessitates an integration of diverse data sources to enhance urban management, particularly in historical contexts where traditional methods may lack necessary specificity. To address this, our research integrates advanced 3D survey techniques (mostly low-cost) with publicly available datasets to develop a semantically rich, detailed urban digital model aligned with specific requirements of each unique urban setting. The methodology hinges on three pivotal stages: data acquisition, data management, and data accessibility. Data acquisition involves collecting extensive data both from existing datasets and 3D surveys, emphasizing on identifying optimal, cost-effective solutions suited to the surveyed area. Data management is achieved using a broker database coupled with a Web Application Programming Interface (Web API), ensuring the integrity of original databases while enabling flexible system implementation. Data accessibility extends to a broad range of applications, including GIS, BIM, and customized applications, enhancing the scalability of the digital twin model. The test ground of this system is a VR application developed with Unity, which serves as the interactive platform for the digital twin model. The proposed framework is validated through three case studies in distinct urban settings, each chosen to illustrate the framework's adaptability, versatility, and effectiveness in different urban complexities. The results demonstrate the potential of the digital twin model in facilitating detailed urban management tasks, promoting sustainable heritage conservation, and fostering smarter urban environments
HBIM for conservation: A new proposal for information modeling
Full text linkThanks to its capability of archiving and organizing all the information about a building, HBIM (Historical Building Information Modeling) is considered a promising resource for planned conservation of historical assets. However, its usage remains limited and scarcely adopted by the subjects in charge of conservation, mainly because of its rather complex 3D modeling requirements and a lack of shared regulatory references and guidelines as far as semantic data are concerned. In this study, we developed an HBIM methodology to support documentation, management, and planned conservation of historic buildings, with particular focus on non-geometric information: organized and coordinated storage and management of historical data, easy analysis and query, time management, flexibility, user-friendliness, and information sharing. The system is based on a standalone specific-designed database linked to the 3D model of the asset, built with BIM software, and it is highly adaptable to different assets. The database is accessible both with a developed desktop application, which acts as a plug-in for the BIM software, and through a web interface, implemented to ensure data sharing and easy usability by skilled and unskilled users. The paper describes in detail the implemented system, passing by semantic breaking down of the building, database design, as well as system architecture and capabilities. Two case studies, the Cathedral of Parma and Ducal Palace of Mantua (Italy), are then presented to show the results of the system's application
Tra conservazione e innovazione: un HBIM per il Duomo di Parma
No full textThe BIM methodology is now more and more widespread. While it is consolidating in the field of new buildings, in the field of Cultural Heritage, many questions are still open. The paper describes an ongoing research on the creation of a HBIM for the Cathedral of Parma, aimed at the planned conservation. HBIM was designed as an information system on the architectural scale. It allows interaction between the 3D model of the building and a specifically structured external database in order to manage all data about the building in a consistent and coordinated way
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