HBIM

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HBIM can be defined as the use of BIM to model existing buildings as part of heritage conservation or heritage revitalization. The complexity of the problem and timeliness of solutions in the field of HBIM can be read in the article - Informative models of architectural heritage - by Martin Attenni [2], below he quotes the most important fragments:

BIM (Building Information Modeling) processes are the most effective way to learn about existing architectural structures, integrating the most advanced 3D modeling capabilities and structured storage of heterogeneous information. Many HBIM (Heritage Building Information Modeling) applications lead to the systematization of measurement data, even though the unambiguous working method has not yet been clearly defined. In this study, the main moments of the HBIM process are the decomposition of architecture based on structured criteria and its reconstruction using ideal models. This hypothesis is verified with a procedure that combines the 3D survey data with the characteristics of an ideal HBIM model, allowing for a continuous comparison of the design model and the as-built condition. The research envisages the formulation of a general methodology which, in line with the growing approach to the complexity of the analyzed buildings, compares the process taking place on two architectural objects. The study examined several important issues related to HBIM: the relationship between semantic modeling and the continuity of architectural heritage surfaces; the relationship between element standardization, geometric irregularities and material heterogeneity; the reliability of the models built; and assessing the discrepancy between the ideal model and the objective accuracy of the measurements.

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The presence on the site of a very large number of existing buildings, many of them of high historical and cultural value, requiring more or less decisive transformational interventions, was conducive to the extension of the 2014 European Directive (EUPPD 2014/24 / EU). It promotes a new approach to the entire construction process (design, representation, construction, management and maintenance) and encourages the use of BIM not only for new construction interventions, but also for renovation, adaptation or maintenance. In this context, the relationship between these operations and the knowledge and documentation of the history and present state of artifacts should be kept in mind. They are closely related to the activity of acquiring data on historical heritage. The integration of survey data, now increasingly complete, heterogeneous and shareable, and HBIM systems allows for the introduction of a multitude of information based on reality. This information (metric, geometric, morphological, material, chromatic) is expressed digitally, models allow you to improve knowledge about the building and offer control with the use of obtained data in the development of subsequent projects. The construction industry uses BIM for decentralized planning and control of interventions, but this also has implications for the complex management of architectural heritage. Heritage BIM consists in modeling architectural elements according to their constructive and historical-artistic features [3,4,5]. HBIM processes enable, through digital platforms and integration with survey data, to explore new possibilities for managing cultural heritage data, from general to detailed scale, combining quantitative and qualitative characteristics. The first concerns physical parameters, metric, geometric, morphological and spatial information; the latter, on the other hand, are all conditioned or permanent properties related to the formal aspects of the analyzed structures. However, possible interactions between HBIM and research data continue as the purposes for which BIM systems are developed and used change as they are used for heritage building

This is a reverse engineering operation in which reading and segmenting a point cloud, after recognizing characteristic areas, is the first step to identify surface boundaries that facilitate the modeling process. These activities are semi-automatic or fully automatic, thanks to the progress achieved by systems supported by BIM processes. An analysis of the progress achieved in research and professional experience shows that a big step has been taken to automate the point cloud modeling process. Software algorithms and plug-ins can be easily applied to segmentation and automatic modeling of point clouds that describe flat surfaces or primitive geometries. However, they produce incorrect results when trying to represent the geometries of complex and irregular historical buildings. 3D modeling of any artifact implies an organized and structured composition of digital elements, but when applied to HBIM, it must go beyond a typical workflow. An ambitious goal of being the best e matching the real object to the virtual model makes it necessary to structure various phases in order to define and optimize the workflow. The heterogeneity of built heritage means that the definition of structured protocols is useful for demonstrating the characteristics of the case study because the BIM process was not designed to study built heritage. The application of the BIM methodology to the architectural heritage is possible thanks to the continuous technological progress, but also taking into account its theoretical implications when proposing new implementations. Scientists involved in the HBIM study developed various methods and applied technologies for 3D modeling of existing historic buildings and the use of parametric components. A thorough examination of the existing literature, but also of ongoing research, shows how the BIM approach to architectural heritage can be implemented using three different approaches. The first category includes those studies that have only adopted commercial platforms for BIM processes to create models of the existing architecture by creating libraries of parametric objects. The second category is for research that combines BIM systems with support tools or plugins, including open source software or commercial data storage and management (aka GIS). The third category is research linking HBIM with web applications.

Models (and HBIM) via the Internet The evolution of ICT enables the use and access to heterogeneous information thanks to technologies that can understand different languages ​​and place them in Communication. Technological advances also included the field of BIM and HBIM and the creation of web-oriented interfaces that collect data under a single information model. The experience of Quattrini et al. (2017) [21] is important because the group developed the methodology in a particularly complex context. The research carried out at the Church of Santa Maria in Portonovo in some way allows to summarize all the problems identified so far in the field of HBIM. The paper proposes a realistic solution for demanding (almost) complete interoperability between BIM models rich in information organized in a hierarchical manner using ontologies and their queries in the context of a semantic web. The process used is interesting because of its approach at different depth levels; second, the way a semantically structured 3D model is made available in a commonly used browser environment. The user views the data by querying and thus accesses 3D / 2D models or parts thereof, digital worksheets and multimedia content such as PDF files, videos, images or web links. The methodology used shows that it is possible to move from a parametric representation of HBIM to the management of three-dimensional network objects. This operation allows for a better understanding of individual elements through thematic information about the architectural organism and enables the description of semantic content by linking it to thematic databases (construction technologies, abacus elements, etc.). In fact, the use of BIM processes to improve and manage heritage affects three different aspects: knowledge, modeling, and data validity. The main difference is the role of knowledge in HBIM in relation to that required in the design process. In this case, the knowledge of the architecture being built coincides with the semantic modeling. It is a consequence of the processing of survey data, and if it is set in relation to archival documents, it allows the information to be understood through the correct interpretive context, and thus it can be made available by optimizing programming and performing subsequent operations. Parametric and informational modeling of historical heritage is difficult, both in terms of geometric transposition of the continuity of the real world and its qualitative description. These difficulties are also related to the intrinsic rigidity of the parametric modeling process and the construction of digital object libraries, which interfere with the variability and uniqueness of the built environment, especially when it has ancient roots or is the result of stratification of various interventions. or is in poor condition. Modeling in HBIM processes involves an important discretization operation that still faces the impossibility of using automated systems to discover these functions. Different BIM platforms allow different types of control of the built model to detect any collisions between disturbing elements or compliance with reference regulations. Reference was made to the collision detection function, in the second case to the mode checking functions allowed by Autodesk Revit software, which are respected in the field of design (e.g. about the fire resistance of the materials used). Extension of BIM processes nand the built legacy highlighted two other types of controls for validating the built models. These are the metric and geometric correspondence between the numerical model and the parametric model, and secondly, the semantic decomposition of the model. In this respect, recent academic research has proposed the introduction of the reliability level (LOR) as an indicator of the reliability of the information model or its digital objects [22]. Reconsidering these aspects opens possible development scenarios for the implementation of consolidated methods of integrated research and interventions in cultural heritage using information systems, in order to guarantee an increasingly controlled data structure that influences the scientific nature of the whole process.

Another assessment is the LOR (level of confidence). It shows how knowledge processes are always gradual, associated with the continued possibility of new research and the interpretation of heterogeneous information (Fig. 14). The control of the semantic structure of digital objects implies more complex dynamics, less objective than those related to the geometrical consistency and the correct structure of models. In fact, there are no applications similar to the model reviewer application that allow you to perform critical semantics checks in HBIM. An important proposal in this field concerns the coding of a new parameter that can fill the shortage of standard parameters that measure the reliability of technical information in BIM processes. For LOD and LOI (level of information), recent studies add LOR (level of confidence), which measures reliability in terms of the overall consistency of the process defining any digital object [42,43,44]. The parameter links the geometric reliability of digital objects with their ontological compliance with the actual shape they describe. Several factors influenced the geometrical reliability of the model: parameterization of the geometrical shape of the elements; identification of geometric and compositional rules; and the comparison of the obtained data (through geodetic operations or through archival sources) with the parametric model. The factors influencing the ontological correspondence of digital objects are much more complex to analyze, because they come from subjective actions and take up the problem of crossing the examined surface. In this case, they take over the data relating to the phases of the object's evolution; knowledge of building techniques and materials all data used is obtained from additional studies (stratigraphy, matching of architectural or structural elements, etc.); identification by analogy with contemporary or similar buildings. The definition of the reliability level is governed by a numerical scale from 0 to 10 for each digital item with respect to the corresponding architectural item. LOR 0 represents a symbolic digital object, while LOR 1 is reserved for known objects in very fine detail. A diagram constructed in this way not only simplifies the reliability of each modeled digital object, but can also be useful in the process of artifact decomposition and reconstruction, in which the end result is included in the information model as one of the attributes of the digital object (Table 1).

In the model of modern architecture, the mutual organization of elements (columns, beams, floors, walls, etc.) has been established according to the standards of the era, and all digital objects are characterized by BIM attributes (materials, constructive layers, etc.), getting very close to the finished building. Loss model On the other hand, a complex complex is a synthesis of several ideal models that represent the evolutionary phases of construction up to the present state. The historical research results are; therefore it is necessary to collect and select the necessary information from texts, photos, drawings, videos, and often from other unpredictable sources that describe the design of the original building not only in terms of geometry, but above all in terms of technology, material and constructive point of view. Currently, BIM processes do not take this aspect into account and relate mainly to the configuration of objects at present. However, major applications include tools to represent the temporal location of an object using graphical substitution rules widely used in the design field to identify demolition and reconstruction operations. In HBIM processes, these features can be used to describe each phase of a building's life using a model or vice versa, each object that makes up the model can be distinguished by the attribute of belonging to a specific historical phase or at different times, data acquisition. The individual models are connected not only from a logical, technological, semantic and constructive point of view, but also from a time point of view, overlapping and following the principles of BIM processes with regard to families and connection laws.

Sources:

[1] pixabay.com; author: just-pics

[2] Martina Attenni; Informative Models of Architectural Heritage - Department of Historii, Representation and Restoration of Architecture, Sapienza University of Rome, 00187 Rome, Italy Heritage 2019 - https://www.google.com/url?q=https%3A%2F%2Fwww.mdpi.com%2F2571-9408%2F2 % 2F3% 2F125% 2Fpdf & sa = D & sntz = 1 & usg = AFQjCNGsynSbX4f_sAhhbD0VwaQVOZO1ww