1,721,006 research outputs found
Water: Social Responsibility and the Concept of Common Good in the Ancient City of Pompeii
Get PDFPompeii was connected to the great Serino aqueduct under the principate of Augustus. From that moment on, water became not only a precious resource for the inhabitants but also their true social indicator. It is no coincidence, in fact, that the concentration of sumptuous dwellings is in Regio VI, the district closest to the aqueduct reservoir (castellum aquae in Latin) and the one most equipped with piezometric towers, the first of the network, the ones that would never leave the decorative fountains of the peristyles dry. From this observation follows the original possibility of considering the water network a factor that contributed to designating the morphology of urban neighbourhoods and blocks
La Tomba di Giulio II a Roma: dal rilievo fotogrammetrico alla stampa 3D per non vedenti
Get PDFLa stampa 3D di manufatti e monumenti consente alle persone non vedenti e ipovedenti di scoprire, comprendere e godere della bellezza del patrimonio culturale. La riproduzione dei manufatti inizia solitamente con il rilievo 3D con tecniche basate sulla realtà al fi ne di ottenere la loro copia digitale metrica e accurata. Con una corretta post-elaborazione, il modello digitale viene quindi predisposto per la stampa. Il risultato è un modello fi sico che può essere toccato e ispezionato, rendendo l’arte visibile a tutti.Questo articolo presenta la pipeline seguita per la riproduzione 3D della famosa Tomba di Giulio II di Michelangelo, visibile nella chiesa di San Pietro in Vincoli a Roma. Il rilievo fotogrammetrico viene descritto e valutato, e tutto il processo seguito per post-elaborare il modello 3D al fi ne di renderlo computabile per la stampa 3D. Particolare attenzione è stata data ai problemi verifi catisi durante il rilievo (mancanza di spazio, luci) e quindi la post-elaborazione relativa alla creazione di diversi modelli fi sici stampati. I modelli fi nali sono stati stampati in accordo con le richieste del cliente, in modo da renderli adatti ai non vedenti
A GEOMETRIC PROCESSING WORKFLOW FOR TRANSFORMING REALITY-BASED 3D MODELS IN VOLUMETRIC MESHES SUITABLE FOR FEA
No full textConservation of Cultural Heritage is a key issue and structural changes and damages can influence the mechanical behaviour of
artefacts and buildings. The use of Finite Elements Methods (FEM) for mechanical analysis is largely used in modelling stress
behaviour. The typical workflow involves the use of CAD 3D models made by Non-Uniform Rational B-splines (NURBS) surfaces,
representing the ideal shape of the object to be simulated. Nowadays, 3D documentation of CH has been widely developed through
reality-based approaches, but the models are not suitable for a direct use in FEA: the mesh has in fact to be converted to volumetric,
and the density has to be reduced since the computational complexity of a FEA grows exponentially with the number of nodes.
The focus of this paper is to present a new method aiming at generate the most accurate 3D representation of a real artefact from highly
accurate 3D digital models derived from reality-based techniques, maintaining the accuracy of the high-resolution polygonal models
in the solid ones. The approach proposed is based on a wise use of retopology procedures and a transformation of this model to a
mathematical one made by NURBS surfaces suitable for being processed by volumetric meshers typically embedded in standard FEM
packages. The strong simplification with little loss of consistency possible with the retopology step is used for maintaining as much
coherence as possible between the original acquired mesh and the simplified model, creating in the meantime a topology that is more
favourable for the automatic NURBS conversion
3D Reality-Based Survey and Retopology for Structural Analysis of Cultural Heritage
Get PDFCultural heritage’s structural changes and damages can influence the mechanical behaviour of artefacts and buildings. The use of finite element methods (FEM) for mechanical analysis is largely used in modelling stress behaviour. The workflow involves the use of CAD 3D models and the use of non-uniform rational B-spline (NURBS) surfaces. For cultural heritage objects, altered by the time elapsed since their creation, the representation created with the CAD model may introduce an extreme level of approximation, leading to wrong simulation results. The focus of this work is to present an alternative method intending to generate the most accurate 3D representation of a real artefact from highly accurate 3D reality-based models, simplifying the original models to make them suitable for finite element analysis (FEA) software. The approach proposed, and tested on three different case studies, was based on the intelligent use of retopology procedures to create a simplified model to be converted to a mathematical one made by NURBS surfaces, which is also suitable for being processed by volumetric meshes typically embedded in standard FEM packages. This allowed us to obtain FEA results that were closer to the actual mechanical behaviour of the analysed heritage asset
A Geometric Processing Workflow for Transforming Reality-Based 3D Models in Volumetric Meshes Suitable for FEA
Get PDFConservation of Cultural Heritage is a key issue and structural changes and damages can influence the mechanical behaviour of artefacts and buildings. The use of Finite Elements Methods (FEM) for mechanical analysis is largely used in modelling stress behaviour. The typical workflow involves the use of CAD 3D models made by Non-Uniform Rational B-splines (NURBS) surfaces, representing the ideal shape of the object to be simulated. Nowadays, 3D documentation of CH has been widely developed through reality-based approaches, but the models are not suitable for a direct use in FEA: the mesh has in fact to be converted to volumetric, and the density has to be reduced since the computational complexity of a FEA grows exponentially with the number of nodes
3D surveying and modeling of archaeological sites - some critical issues
No full textThe goal of the reported project is to test and evaluate 3D surveying and modelling methods to document the remaining ancient byzantine city walls of the archaeological site of Aquileia in Friuli Venezia Giulia, Italy. The objectives are threefold: (1) to use 3D data to create maps, façades and sections that provide information useful for archaeological purposes such as the investigation of architectural construction techniques or construction phases, (2) to evaluate and compare photogrammetric and laser scanner data in order to identify the advantages and disadvantages of the two 3D surveying techniques for archaeological applications and needs and
(3) to draw broader conclusions about the applicability of photogrammetry and laser scanning for documenting and analysing ancient walls within a particular set of environmental circumstances. The paper presents the employed 3D surveying techniques, the obtained 3D results and 2D products and some critical comments
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