1,722,569 research outputs found
Reality-Based HBIM for the Management of Monumental Architectonic Heritage
No full textThis paper will describe relevant experiences of the 3DSurvey Group of the Polytechnic of
Milan while working on one of the leading Italian monumental cathedrals, the Duomo of
Milan. The document presents some critical aspects of the multi-year activity in collaboration
with the Veneranda Fabbrica del Duomo di Milano; this started in 2008 and is still active
today. The primary purpose of the research project as it was born in 2008 was the highresolution and high-accuracy 3D survey (representation scale of 1:20-1:50) of some parts
of the cathedral to support the different restoration sites. From 2013 onwards, the project
included the survey of the entire cathedral. The first and most important of the sites where
most of the research has been carried out is the main spire, which began in 2008 and was
completed in 2013. We consider this project pioneering at that time, both as regards the
survey and the activities promoted in the field of the use of the data acquired, with the
creation of an HBIM system designed and developed specifically to support the restoration
activities of the Veneranda Fabbrica. The main difficulty in dealing with cultural heritage is
that each case has specific and unique peculiarities and needs. Furthermore, they require
having non-parametric, high-resolution models that represent reality with high precision and
accuracy, created ad-hoc systems, and easy to use tools to facilitate the interaction among the
systems and all the different stakeholders. The described research project wants to present
an alternative solution to the classical/commercial HBIM approach—the creation of an
information system capable of adapting to 3D models that have different scales to support
different maintenance requirements as well as different information data and management
tools
HANDHELD FISHEYE MULTICAMERA SYSTEM: SURVEYING MEANDERING ARCHITECTONIC SPACES IN OPEN-LOOP MODE - ACCURACY ASSESSMENT
Full text linkThe 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 using static devices becomes prohibitive and the accuracy using mobile devices gets affected by drift error leading to warped models or requiring abundant control measurements. This paper presents a photogrammetric portable fisheye multicamera solution for the 3D survey of complex areas that aims at being both handy and fast in the acquisition as well as more reliable ad accurate than common MMSs. The paper showcases a stress test conducted on five complex reconstruction trajectories selected from the meandering connection passages of Milan's Cathedral. The tests are constructed as worst-case scenario to evaluate the accuracy and drift error amount of the proposed system in open-ended unconstrained paths. The results, though still suffering from moderate drift error, highlights the potential of the solution, especially in retaining the overall shape and orthogonality of the architectonic elements acquired
BACKPACK MOBILE MAPPING SOLUTION for DTM EXTRACTION of LARGE INACCESSIBLE SPACES
Full text linkThe 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 other. The framework within which this research takes place is the Fort of Pietole survey project that aims at the extraction of the Digital Terrain Model (DTM) of the area and the georeferencing of the fort defensive structures. The requirement of the project is the 3D reconstruction of the whole area at an accuracy that stands between a big scale environmental survey and a small-scale architectonic survey (1 : 500). The project is the opportunity to discuss the state of the art of wearable MMS, and to test the versatility and accuracy outcomes of the Pegasus Backpack under varying and challenging condition (indoor-outdoor, even-uneven pavement, satellite covered-denied areas) with the ambitious goal to use only the backpack MMS to record all the data from the DTM to the indoor narrow structures. © 2019 International Society for Photogrammetry and Remote Sensing. All rights reserved
MIXED REALITY CONTENT ALIGNMENT IN MONUMENTAL ENVIRONMENTS
Full text linkMixed 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 with various levels of data. This can be accomplished by appropriately registering and superimposing the presented 3D models with the surrounding environment. This work aims to provide a quantitative evaluation of HoloLens 2 capabilities in registering virtual content inside monumental spaces. Two different methodologies are evaluated: Vuforia image targets and Microsoft World Locking Tools (WLTs). Tests have been performed inside Milan Cathedral's monumental spaces. Here, ambience dimensions, single architectural element repetition and non-uniform lighting conditions push out-of-the-box methods to their limits. Results show that WLTs with their space pins API can correctly reference virtual content keeping deviations in the order of 15 cm coping with the scale error produced from sensors' drifts
HoloLens 2 Spatial Mapping Capabilities in Vast Monumental Heritage Environments
Full text linkHoloLens 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-world objects, perform occlusions and simulate physical interactions only having the geometric knowledge of its operating environment. HoloLens 2 mapping capabilities have been extensively tested. Nevertheless, no test was performed on monumental heritage buildings, where dimensions far exceed the typical sensor working range of the device. The authors want to evaluate the capability of the device to map monumental spaces. In these environments, dimensions, repetition of elements and heterogeneity of areas provide a real challenge for out-of-the-box Microsoft localization and mapping algorithms. The test case will be Milan Cathedral, inside the research project to build an MR application to help and enhance the systematic and planned maintenance intervention and inspections. Mapping capabilities have been tested in very different spaces: i) the south nave; ii) the empty volumes between the internal vaults and the external roof ("Sordine"); iii) the narrow spiral staircase connecting the south nave with the roofs lower level
The Hospitable city and health tourism: new forms of "welcoming"
No full textNew forms of hospitality in the contemporary worldwide urban citie
Application of multiple techniques for the survey, 3D modeling and virtual representation of the internal rooms of the Real Villa in Monza
No full textMachine Learning Methods for UNESCO Chinese Heritage: Complexity and Comparisons
Full text linkRecent 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 (MLMR) methodology to classify two point cloud projects in China, Nanchan Ssu, and Fokuang Ssu. Performances of multiple algorithms and solutions are compared, proving the applicability of MLMR on the point clouds. The practices pointed out the significance of corresponding features to classification rules and a sound logic in designing a systematic label tree with hierarchical semantic meanings
PORTABLE MULTI-CAMERA SYSTEM: FROM FAST TUNNEL MAPPING TO SEMI-AUTOMATIC SPACE DECOMPOSITION AND CROSS-SECTION EXTRACTION
Full text linkThe 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 allows for the rapid acquisition of the image dataset needed to produce the 3D data. Moreover, since often, automatic, and fast acquisitions are not supported by easy-to-use tools to access and use the data at an operational level, a second aim of the research is to define a method able to arrange and organise the gathered data so that it would be easily accessible. The proposed approach is to compute the 3D skeleton of the surveyed environment by employing tools developed for the analysis of vascular networks in medical imagery. From the computed skeletonization of the underground tunnels, a method is proposed to automatically extrapolate valuable information such as cross-sections, decomposed portions of the tunnel, and the referenced images from the photogrammetric survey. The long-term research goal is to create an effective workflow, both at the hardware and software level, that can reduce computation times, process large amounts of data, and reduce dependency on high levels of experience
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