1,721,056 research outputs found
Analisi della qualità del rilievo laser scanner architettonico e criteri di verifica
No full textIl rilievo e la sua successiva rappresentazione grafica
sono, come noto, il primo approccio per i processi
di conoscenza, di progetto per la conservazione e il
restauro dell’architettura e, come tale, essi devono
rispondere ai requisiti che la specifica applicazione
richiede.
Mentre il rilievo per la conoscenza richiede
un’interpretazione dell’idea progettuale più che
delle inevitabili discrepanze da esso provocate dalla
realizzazione e dal tempo, il rilievo per un intervento
di restauro richiede per contro la registrazione di
tutti i dettagli così come si presentano da una misura
sufficientemente accurata.
Il rilevamento (rilievo metrico) dovendo contribuire al
rilievo deve quindi adattare le tecniche e i risultati da
raggiungere in base alle finalità che il rilievo si propone
e deve fornire a chi si incarica della rappresentazione
tutti gli elementi necessari in termini di precisione e di
accuratezza.
Indipendentemente dalla tecnica di misura utilizzata è
necessario che sia chiaro, a chi utilizzerà i dati di misura, la qualità metrica e la affidabilità dei dati consegnati in
modo da poter garantire la corretta interpretazione e
il corretto utilizzo dei dati metrici nelle successive fasi
di disegno e rappresentazione.
Per raggiungere questi obiettivi è necessario che
tutta l’operazione di misura venga effettuata in modo
corretto e che al termine si certifichi il prodotto con
una serie di controlli che ne verifichino la completezza
e l’accuratezza secondo i criteri prestabiliti.
La tecnica Laser Scanner Terrestre (TLS) è ormai
considerata tra le tecniche più utilizzate per il
rilevamento dell’architettura quale fase iniziale per una
qualsiasi operazione di rilievo e rappresentazione dello
stato attuale di un oggetto architettonico; il presente
lavoro si concentrerà quindi sulle procedure da
utilizzarsi per l’utilizzo di tale tecnica, tenendo conto
delle sue specificità, e delle buone prassi di verifica in
corso d’opera e al termine delle operazioni di misura
FROM REALITY TO PARAMETRIC MODELS OF CULTURAL HERITAGE ASSETS FOR HBIM
Full text linkThe ability of managing big amounts of metric information coming from a LiDAR survey and the ability to reproduce high quality 3D models from them are still vivid problems to solve. Is it possible to create detailed models, geometrically and metrically correct, without using a large amount (often redundant) of metric data, such as massive point clouds? Obviously yes, but there are several ways to create a fitting 3D model for a specific research. A good solution is given by NURBS based algorithms that ensure high details of modelling. However, NURBS models can't be used directly on BIM platforms, because they need to be parametrized. In this sense, a parametric model is based on real measurements but each object could be interpreted and approximated based on objective and subjective (critic) view and also based on LODs (levels of detail or development) concerning a particular analysis. This kind of modelling of Cultural Heritage assets, fundamental for HBIM creation, need to be correctly planned especially for classification and definition of its historical features connected to an informative system, because nowadays information and then the semantic dimension are a necessary key points towards documentation analysis.
Established this brief introduction, this schematic work will focus on the analysis of FreeCAD open BIM software and Rhinoceros as NURBS 3D modeller for Cultural Heritage is concerned, and whether and how they could integrate their tools for the purpose of managing dynamic high detailed data for the creation of an HBIM platform
GIS and 3D modeling for Cultural Heritage
No full textThe use of digtial technologies inside historical studies isnot a new, but it cannot be considered completely understood as far as thier potentialities are concerned. Sometimes the use of these technolgies is considered just as a different way to represent the results of the historical researches and not a new opportunity to increase the research strategies or to develop new research methodologies, to disseminate the collected data, and the obtained results to the research community. The diffusion of Information technology (IT) knowledge, the availability of automatic acquisition instruments for metric survey of complex shapes and the possibility to use the open source platforms mainly devoted to metric and geographic data management open the use of these technologies to an ever increasing number of specialsts more involved in other disciplines. This article will focus on the use of GIS and 3D modelling disciplines inside the historical researches by fixing for each of them the basic concepts and the main advantages/problems that can arise from this new approach
3D INTERPRETATION AND FUSION OF MULTIDISCIPLINARY DATA FOR HERITAGE SCIENCE: A REVIEW
Full text linkActivities related to the protection of tangible heritage require extensive multidisciplinary documentation. The various raw data that occur have been oftentimes been processed, visualized and evaluated separately leading to aggregations of unassociated information of varying data types. In the direction of adopting complete approaches towards more effective decision making, the interpretation and fusion of these data in three dimensions, inserting topological information is deemed necessary. The present study addresses the achieved level of three-dimensional interpretation and fusion with geometric models of data originating from different fields, by providing an extensive review of the relevant literature. Additionally, it briefly discusses perspectives on techniques that could potentially be integrated with point clouds or models
An Updated Comparison on Contemporary Approaches for Digitization of Heritage Objects
Full text linkContinuous developments on sensors, data acquisition techniques, algorithms and computational systems have enabled automation, higher processing velocities and increased metric accuracy regarding the modeling of tangible heritage. For applications on heritage artefacts or architectural details, scanning and photogrammetric systems based on structure-from-motion (SfM) approach have prevailed, due to lower costs, fast acquisition and processing, re-producibility of workflows and ability to capture high-resolution texture. This study presents an updated comparison of contemporary digitization approaches to examine in extent required processing stages, compare costs and evaluate produced 3D results according to their metric properties, quality of texture and visual fidelity
A NEW HANDHELD SCANNER FOR 3D SURVEY OF SMALL ARTIFACTS: THE STONEX F6
Full text linkMovable heritage preserved in our museums are an invaluable evidence of our past. In order to properly respond to the need of 3D documentation of these significant assets, in the last few years both range-based and image-based solutions have been developed by researchers operating in the framework of Geomatics with a special focus on reaching a high level of detail and on texture radiometric quality, taking into consideration the intrinsic fragility of these kinds of objects which during the survey require a contactless approach. During the presented research a collection of architectural models representing ancient Nubian temples from “Museo Egizio di Torino” had been digitalized using different techniques; in particular, the wooden maquette of the temple of El-Hilla has been acquired using a new structured light handheld laser scanner, the Stonex F6 SR, and applying a close-range photogrammetric approach. In this paper a comparison between the two approaches is proposed as regards acquisition workflow, final results and suitability as regards digitisation of objects belonging to movable heritage and museum collections
BENCHMARK OF METRIC QUALITY ASSESSMENT IN PHOTOGRAMMETRIC RECONSTRUCTION FOR HISTORICAL FILM FOOTAGE
Full text linkQuality assessment in photogrammetric processing is fundamental to obtain metric information and to reconstruct 3D models of Cultural Heritage, especially when it has been lost or changed over time. The determination of metric precision is technically challenging when dealing with historical films and videos that in many cases represent the only remaining traces of this heritage, which is useful for architectural, archaeological and restoration studies. This paper examines the suitability of existing photogrammetric software to evaluate the maximum possible metric accuracy for processing videos shot with fixed camera motions. In order to evaluate the metric quality obtained processing historical film footage with photogrammetric techniques, a benchmark was created on a new video dataset with the aim of reproducing the camera motions in which old video were shot. Three different camera motions were considered: Up/Down Motion-Tilting, Left/Right Motion-Trucking and Rolling Motion-Panning. The methodology was experimented on Valentino Castle in Turin, a monument inscribed in the UNESCO World Heritage List. Data were processed with the implementation of open source Structure-from-Motion algorithms and the results were analysed for the evaluation of metric quality. Results show the different maximum precision assessments according to the different typologies of camera motion. This research provides fundamental support to historical studies on Cultural Heritage, creating a sharing standard with zero-cost data and tools useful for both geomatics and restorers
CULTURAL HERITAGE RECONSTRUCTION FROM HISTORICAL PHOTOGRAPHS AND VIDEOS
Full text linkHistorical archives save invaluable treasures and play a critical role in the conservation of Cultural Heritage. Old photographs and videos, which have survived over time and stored in these archives, preserve traces of architecture and urban transformation and, in many cases, are the only evidence of buildings that no longer exist. They are a precious source of enormous informative potential in Cultural Heritage documentation and save invaluable treasures. Thanks to photogrammetric techniques it is possible to extract metric information from these sources useful for 3D virtual reconstructions of monuments and historic buildings. This paper explores the ways to search for, classify and group historical data by considering their possible use in metric documentation and aims to provide an overview of criticality and open issues of the methodologies that could be used to process these data. A practical example is described and presented as a case study. The video “Torino 1928”, an old movie dating from the 1930s, was processed for reconstructing the temporary pavilions of the “Exposition” held in Turin in 1928. Despite the initial concerns relating to processing this kind of data, the experimental methodology used in this research has allowed to reach a quality of results of acceptable standard
A Survey of "The Sala degli Stucchi, an ornate baroque hall"
No full textThe "Sala degli stucchi" is a heavely decorated baroque hall, as the Italian name itself suggests, in the Royal Palace in Turin. The present work describes a survey of this historic object. This work is a part of a wider project on the study of Architectural Patrimony carried out for the La Soprintendenza per il Patrimonio storico, artistico ed etnoantropologico per il Piemonte. It is a chance to test the modern survey techniques of photogrammetry and LIDAR. This article focuses on the integrated use of digital photogrammetry and LIDAR in a demanding environment, in order to take best advantages of both techniques. Different survey products were obtained, ranging from 3D and photogrammetric models to orthophotos. The adopted techniques, the problems and difficulties that arose during the survey process are shown in the paper. The obtained and stored results were also used to make a complete 3D model of the whole hal
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