## 1 Research Background  
How to apply digital technology to preserve the background and footprints of historic buildings during their conservation is an important topic, and new opportunities appear with the rise of the emerging digital technology. The establishment of a semantic BIM model for historic buildings and parameterization of its component information are regarded as effective solutions to enhance future applications of BIM models for historic buildings, and they are an opportunity to initiate sustainable management and diverse applications.  
In addition to providing accurate recording and realistic presentation, 3D visual information-based modeling is an important tool for analysis, reconstruction, and virtual presentation, and can be used to expand the user's ability to explore and interact with the historic block's environment. Regarding the conservation and representation of cultural heritage, in addition to simplifying integration and facilitating a better understanding of heterogeneous information, the visual interactive environment is developed to provide integrated applications with a wide range of information and large amounts of data suitable for historic blocks. However, in spite of the sufficient information on the details of urban blocks and the volume of buildings, BIM research is mostly focused on the study of 3D model visualization; thus, users lack the capability of interacting with and feeding back the surrounding environment in real-time.  
In recent years, virtual reality technology has been expanded to apply to cultural heritage conservation and representation, which provides users with an environment to interact with and give feedback regarding scene objects in real-time, and thus, presenting new possibilities for the workflow and cognitive mode of cultural heritage conservation and representation. Through its real-time visual control and virtual reality performance, VR has been proven to provide an effective communication platform [1] and many scholars are currently conducting research on importing established BIM models into an environment that users can navigate and interact with [2].  
Among them, the application of game engines in 3D model visualization has gradually become a research trend of concern [3; 4; 5; 6; 7; 8], as it provides a high degree of interactive experience, as well as effective communication and an integration environment. Moreover, as the BIM model contains a lot of geometric and non-geometric information, it is the perfect candidate to be imported into the game engine to build a realistic virtual environment.  
As an effective solution, this study selected an open-source game technology platform to import the semantic BIM information model into the game engine platform, which focuses on how to import the existing BIM model for historic buildings into the engine platform, optimizes the restoration process of historic buildings in conjunction with the development of an interactive program, and intensifies the operation and presentation of historic building environments with the aid of game technology. In addition to expansions and making access to data more convenient, game technology can be used for intuitive interaction and management of historic scene information to make best of restoration information, and future applications of historic building models can be expanded during the restoration design, which will reduce the probability of misunderstandings during communication.