BIM Model Integrated Web Visualization Technology Based On 3D Tiles

The three-dimensional visualization of geospatial information has always been an important content of geographic information systems and applications.In recent years,the rapid development of oblique photogrammetry technology has provided an effective means for obtaining a wide range of high-precision 3D models of real objects.However,the three-dimensional model formed by oblique photogrammetry is essentially a digital surface model.The oblique photogrammetry data generated by aeronautical platforms such as drones can only create three-dimensional surfaces on the outside of urban buildings,but cannot describe the details of their internal models,resulting in the lack of three-dimensional geographic information system’s ability to describe the internal information of buildings.Building Information Modeling(BIM)is a data model that standardizes the description of each component of a building in the field of construction,and can achieve accurate representation of building internal details.Therefore,combining the oblique photogrammetry 3D model with the BIM model and using their respective advantages to achieve integrated description and visualization of large urban scenes from the outside to the inside,has begun to attract the attention of the academic community,and has become the current 3D visualization of geospatial information Research and application hotspots.The Web is an important application environment for current geographic information systems.The combination and integration of 3D models of oblique photogrammetry and BIM models under the Web face many challenges.First,because both the oblique photogrammetry 3D model and the BIM model have a huge amount of data,it is difficult to use traditional data loading methods to transfer the required data into the visualization area.Secondly,the huge amount of data has also brought a huge Due to the pressure,the existing network transmission scheduling strategies cannot meet the requirements of instant interaction in 3D scenes.Based the above problems,a dissertation conducts research on the integrated visualization technology of 3D model of oblique photogrammetry and BIM model under the Web environment.The main work and results are as follows:1.Aiming at the problem of rapid transmission,analysis and rendering of the BIM model based on the large-scale oblique photography model on the web side,a BIM pyramid data organization structure based on a three-dimensional tile model was proposed to achieve a multi-resolution level of detail for the BIM model The organization,through the selection and elimination of the meta data in the BIM model,completed the lightweight processing of the BIM model for web applications,and improved the efficiency of BIM model transmission and analysis.2.Aiming at the problem of quickly visualizing the 3D tile-based BIM pyramid model,a viewpoint-based dynamic scheduling optimization algorithm was proposed to optimize the BIM model loading and dynamically load the 3D tiles of the BIM model according to the viewpoint position and the cone range.Controlling different resolution levels of detail required by the scene improves the loading and rendering performance of BIM models.3.Based on the unified geospatial framework,the registration and flattening coverage algorithm of the three-dimensional model of oblique photogrammetry and BIM model are proposed,and interactive technologies such as integrated lighting,internal and external interactive roaming,and detailed feature information extraction of building models are designed.Web BIM model and oblique photography 3D model comprehensive visualization prototype system.The method proposed in the dissertation effectively reduces the amount of data to be loaded and transmitted by the BIM model in the network environment,improves the continuity and fluency of 3D geographic information visualization,and makes the rendering frame rate of the BIM model more stable when the scene changes dynamically.