The Field Trip for Measured Survey of Built Heritage carried out by Tianjin University every summer aims to educate students in each practice session, i.e., on-site data acquisition, condition investigation, classification of the component library, taking observation notes, and accomplishing HBIM deliverables. Under the risks posed by the ongoing COVID-19 pandemic, the students could not leave the campus as a provisional arrangement. Only a team of five people was allowed to visit the Kuiwen Pavilion in the Temple of Confucius (Qufu, China). Therefore, the field trip for students had to be replaced with remote solutions, which consists of the following methods: on-site data acquisition; post-processing; online education, observation, modeling, delivery. Kuiwen Pavilion in the Temple of Confucius is a library with the official architectural style of the Ming and Qing Dynasties (14th to 20th century), for which building regulations are commonly recognized, and are suitable for survey education. In this context, this article focuses on the remote practice methods applied and tested throughout the case study. During the practice of the course, students who managed to finish the course, through the virtual tours and other online methods, finally achieved delivery of the HBIM models.

Historic building information modeling (HBIM) provides an index frame for digital documentation of the cultural heritage, as a continuous process of reverse engineering. The index frame should be a regular model, with a clear comprehension of each component; consequently, associated knowledge could be live-updated with the investigation progress. Therefore, the method of data registration stresses its importance. The axis is fundamental for Chinese traditional architecture as the basis for positioning all components in wooden structures. However, displacement often happens. To correct the displacement while modeling, the hypothetical axis should be determined first. This paper thus proposes a method of generating the regular axis from irregular column grids and aims to develop an automatic solution that is repeatable and transplantable. The finite element modeling (FEM) abstracts the actual problem to enable numerical calculation. Starting from a candidate solution, the genetic algorithm calculates a solution closest to the expectation from the possible solutions in several minutes. The standard deviation is used to measure the amount of displacement based on the hypothetical axis, which is expected to be minimum. This method is compatible with most kinds of input data, e.g., point cloud, excel data, 2D drawing, mesh model, etc., and applied to a World Heritage Site in Qufu (Shandong, China). The results show the displacement of columns with visual expression and numerical analysis and prove that the proposed method is repeatable and traceable and can easily be applied to different projects by changing input parameters.

Historic Building Information Modelling is a continuous process based on reverse engineering of built heritage. By reviewing the research on HBIM with the case study, this article analyzes the combination logic between different components, based on which designs an algorithm program for automatic model generation, and proposes a regularized rebuild workflow to realize the informatization and parameterized documentation of built heritage. This article proposes the parametric workflow based on Rhino + Grasshopper + Revit / OpenBuildings Designer, establishes the information index framework under the guidance of the HBIM model, and proposes the key technologies of informatization and parameterization of architectural heritage protection records. With reference to the point cloud, mapping map, survey photos, and documents, the regularized rebuild is carried out, and all the parameter nodes are visualized to facilitate error correction and modification. The framework of the regularized rebuild workflow is defined, and the problems of packet grouping principle, component combination mode, and output type are solved, and the algorithm principle is described in detail. According to the construction logic, the single building consists of six parts: tile roof, rafter, wooden carpentry, wall, decoration, and foundation. The work of investigation, modeling, and additional professional data are carried out by parts and items to create a "digital twin". This article solves the modeling problem of complex shape and node, and further improves the working method during the survey, and proposes to use an algorithm module to realize real-time association between professional data and model. Taking the grid system, wall brick, balustrade, tile roof, rafter as examples, through compiling and debugging in Grasshopper compiler environment, according to different input parameters, the program automatically outputs the corresponding model and contains professional data, which proves that the program is fast and accurate. The regularized rebuild workflow for HBIM by reference to point cloud is realized.

In 2015, the Study of Xi’an Historic Walled City Regeneration Strategy applied the Historic Urban Landscape (HUL) Approach through experimenting and testing digital technologies following recommended action steps of HUL Approach. Within the context of urbanisation and heritage deterioration happened past decades in Chinese cities, this paper proposes an innovative HUL Information System that can be used to integrate the approach and technical support measures. This enables comprehensive identification of spatial–temporal relativity of urban landscape morphology, linking between the past and present. The use of spatial digital tools such as aerial photo modeling, geographic information system analysis, and space syntax is explored to trace the continuity of the historical landscape in the built environment. The research team uncovered the context of Xi’an’s cultural and historical landscape through historical literature and related studies over past decades, and summarised and obtained a spatial data set for the dominant historical landscape pattern of the walled city area. Compared with the existing spatial pattern identified by digital tools, the findings showed similarity with historical landscape patterns, including part of a fengshui landform, the 17th to 19th century water system, and an evolving community habitat. This could be explained by the literature and academic research, which demonstrates the influence of historic landscape system in urban evolution. This research aims to show the potential of the HUL Information System as a technical support for urban conservation in Chinese cities, particularly with regard to mapping resources, which is fundamental toward other relevant steps in the HUL approach.

The grid system of traditional Chinese timber structure building is generally rectangular or in other regular geometric shapes. Due to construction errors, building deformation and other reasons, the actual grid system obtained by laser 3D scanning technology is usually not in regular shape. The purpose of HBIM is to favor regularity, and it is necessary to carry out regularized reconstruction on the grid system. By reconstruction of the grid using genetic algorithm in Grasshopper, feasible regularized HBIM models can be obtained.

The investigation of cultural heritage is a continuous process, in which a large scale of metadata is gradually accumulated, i.e., condition data, intervention data, and the comprehension of building techniques. We take the roof tile of Yangxindian Palace as an example. The total number of roof tiles is 17,154. Their positions are various, as they are equally distributed on double-curved irregular surfaces. Their metadata are multisource and heterogeneous. Therefore, the integration between the model and the data can be complex. This paper aims to generate the M1 (metalevel) model with its graph database based on the M3 (metalevel) model through algorithm modeling. This synergy approach consists of three parts. First is the data collection. The unique identifier is used as the index while investigating onsite, which eventually forms the metadata repository. Second is the algorithm modeling. All the roof tiles are rebuilt in Grasshopper with identifiers. Their metadata are merged through Cypher syntax, which can generate the graph database in Neo4j. Third is the delivery. The IFC model and knowledge graph are connected in real time during the whole process. The significance of this paper is to provide a synergy approach and discuss its efficiency for the integration between a model and data of very large quantities. The results show that it is efficient to express the semantic relationships of both conditions and interventions. It is practicable to lightweight the IFC model and to associate metadata into the graph database, enabling online browsing and querying.