Models and scales for quality control: toward the definition of specifications (GOA-LOG) for the generation and re-use of HBIM object libraries in a Common Data Environment

Abstract

The paper focuses on new opportunities of knowledge sharing, and comparison, thanks to the circulation and re-use of heritage HBIM models by means of Object Libraries within a Common Data Environment (CDE) and remotely-accessible Geospatial Virtual Hubs (GVH). HBIM requires a transparent controlled quality process in the model generation and its management to avoid misuses of such models once available in the cloud, freeing themselves from object libraries oriented to new buildings. The model concept in the BIM construction process is intended to be progressively enriched with details defined by the Level of Geometry (LOG) while crossing the different phases of development (LOD), from the pre-design to the scheduled maintenance during the long life cycle of buildings and management (LLCM). In this context, the digitization process—from the data acquisition until the informative models (scan-to-HBIM method)—requires adapting the definition of LOGs to the different phases characterizing the heritage preservation and management, reversing the new construction logic based on simple-to-complex informative models. Accordingly, a deeper understanding of the geometry and state of the art (as-found) should take into account the complexity and uniqueness of the elements composing the architectural heritage since the starting phases of the analysis, adopting coherent object modeling that can be simplified for different purposes as in the construction site and management over time. For those reasons, the study intends (i) to apply the well-known concept of scale to the object model generation, defining different Grades of Accuracy (GOA) related to the scales (ii) to start fixing sustainable roles to guarantee a free choice by the operators in the generation of object models, and (iii) to validate the model generative process with a transparent communication of indicators to describe the richness in terms of precision and accuracy of the geometric content here declined for masonry walls and vaults, and (iv) to identifies requirements for reliable Object Libraries.

Computer Vision Meets Image Processing and UAS PhotoGrammetric Data Integration: From HBIM to the eXtended Reality Project of Arco della Pace in Milan and Its Decorative Complexity

“…Once the various NURBS objects were transformed into BIM parametric objects, thanks to the verification of the grade of accuracy (GOA), it was possible to communicate the reliability of each element created thanks to point set deviation analysis. In particular, thanks to an automatic verification system (AVS), the standard deviation between point clouds and BIM objects was calculated [ 23 , 56 , 57 ]. The value reached for every single element allowed us to define a GOA of about 1–2 mm.…”

Building archaeology informative modelling turned into 3D volume stratigraphy and extended reality time-lapse communication

“…It should also be noted the importance of declaring the reliability of the model and the grade of accuracy (GOA), level of geometry (LOG) and scales achieved for this type of 3D analysis (Banfi, 2020). At this specific point of the process, BIM parameters were developed to declare the geometrical reliability (quality check) of the various BIM objects with respect to reality (Brumana et al, 2021). The values identified are the following: scale 1:50 with a GOA 50 for the HBIM model, scale 1:20 with a GOA 20 for the decomposition into sub-elements of the main façade (Fig.…”

The Evolution of Interactivity, Immersion and Interoperability in HBIM: Digital Model Uses, VR and AR for Built Cultural Heritage

“…Geometry, accuracy and associated information become determining factors for defining LODs for built heritage. Consequently, the need arose to orient the main international guidelines of LODs to heritage buildings, defining scan-to-BIM parameters that accurately describe the quality of the model and its reliability for different types of analysis [71,72].…”