Hbim Level of Detail-Geometry-Accuracy and Survey Analysis for Architectural Preservation

Abstract

<p><strong>Abstract.</strong> The development of advanced survey techniques in the last years is offering a wide set of tools for implementing the building analysis. In the preservation field, the use of 3D interactive models is a prerogative of few and rare excellent cases and the information contained in high-resolution virtual representation are only partially developed. In the past centuries, the representation was centred on the theoretical roles of the descriptive geometry devoted to the representation of the architectural elements complexity in the space to manage the construction site process. It has been progressively lost the past skill to managing 3D objects in the space. Being HBIM based on 3D solids representation, the theme of the 3D model comes back to the foreground. The complexity of the architectural heritage and its components is evidencing a gap of best practices, protocols and specification in the HBIM-modeling. Do-It-Yourself modeling process has been characterised by the first phase of HBIM generation in the last years. Modeling phase within HBIM is left to the single responsibility, with lack of specification on the accuracy and level of geometry.</p><p>This paper presents a first tentative to summarize the relationship among the surveying accuracy, the Level of Geometry and the Level of Accuracy (LOA) of each BIM object, starting from a series of experiences, in which advanced survey techniques were applied to condition assessment required by architectural preservation HBIM approach. The objectives of the surveying and HBIM can change for different aspects: but in the preservation context the specificity of each single objects and their complexity need to be taken into account. As in the surveying, the choice of a scale implies a range of accuracy and tolerance in the data acquisition and processing, in HBIM modelling the choice of the Grade of Accuracy drives within the Level of Geometry the scale model that is expected to be performed and required by the different actors involved by the different phases (i.e. restoration, Energy Efficiency, Finite Element Analysis, CoSiM). On the base of different experiences occurred in the last years, the specifications conventionally adopted for the surveying have been here proposed and extended to the HBIM domain, particularly in the modelling of objects, in order to classify different accuracies. A transparent choice of accuracy allows to define the LOG and to support the adoption of the proper Grade of Generation among the different options (GOG1-10) in function of the point clouds geometry and of the scales chosen by the different actors. The architectural scale together with the urban scale (Heritage Urban Level) is considered as well to keep advantage of a multi-resolution model, diversified in function of the objectives, thus of Level of accuracy (and Level of Information) and Level of Geometry.</p>

HBIM, 3D drawing and virtual reality for archaeological sites and ancient ruins

“…The most modern 3D surveying techniques such as laser scanning and digital photogrammetry (Alby et al, 2019, Barba et al, 2019Riveiro, & Lindenbergh, 2019;Böhler & Marbs, 2004;Masiero et al, 2019) allow professionals to represent buildings with new LOI and LOD (Brumana et al, 2019). In recent years, the benefits of BIM for heritage buildings (HBIM) have been found in various sectors such as structural analysis (Barazzetti et al, 2015, Dore et al, 2015, Korumaz et al, 2017 construction sites (Kumar & Cheng, 2015), restoration (Biagini et al, 2016, Trizio et al, 2019 and facility management (Kang & Hong, 2015).…”

“…In recent years, the development of the most modern 3D survey techniques, digital modelling and mixed reality (XR, virtual and augmented reality VR-AR) has led to the generation of complex models able to represent the heritage buildings with different levels of information (LOI), and detail (LOD) (Brumana et al, 2019;Georgopoulos 2018a;Grussenmeyer et al 2008, Ioannides et al, 2017, Lerma et al, 2010. As we saw recently, it has been possible to increase the reliability of digital models also for more complex architectural and structural elements such as irregular vaulted systems, walls damaged by earthquake destructive action, double curvature walls with variable section and wall stratigraphy characterized by the use of different materials such as stone and brick (Banfi 2019;Brumana et al,2018;Khalil & Stravoravdis, 2019, Oreni et al,2014Stanga et al, 2017;).…”

A Method for 3D Reconstruction of the Ming and Qing Official-Style Roof Using a Decorative Components Template Library

“…LoD 500 provides the geometric details of external and internal forms and new levels of information sharing for different purposes. Brumana et al [44] discussed the HBIM level of detail-geometry-accuracy. In their work, they adopted a scale ranging from 1:1000 to 1:10.…”

Condition Assessment of Rc Bridges. Integrating Machine Learning, Photogrammetry and Bim

“…Few articles investigated how to describe an existing building with BIM, and the relationship between digital survey and BIM models (Murphy et al, 2009). In relation to this wide theme, one of the most interesting topics is the relationship between asbuilt geometry provided by the point cloud and abstracted geometry provided by the model (Brumana et al, 2019). Deviance analysis may provide automatically indexes about structural issues in historic buildings and bridges (Giordano et al, 2015).…”