Research On Digital Modeling Of Modern Architecture Based On 3d Laser Scanning Technology

Perfect drawing data is the key to the reinforcement,repair and reconstruction of ancient buildings.A large number of architectural cultural relics can not meet the requirements of building repair for the lack of drawings.The traditional surveying and mapping method is inefficient and easy to cause secondary damage to buildings during the surveying process.Most building models created by point clouds only focus on the rendering of architectural appearance and the models do not contain specific component information needed for building reinforcement and repair.Based on this,this paper gives full play to the characteristics of high efficiency,non-contact and high precision of 3D laser scanning technology,and studies the acquisition and processing of point cloud information and digital modeling of modern buildings.In this paper,the structure of the three-dimensional laser scanning system and the principles of distance measurement,angle measurement and scanning positioning are deeply studied.The key issues such as scanning steps and site erection in the process of point cloud field data collection,point cloud splicing,denoising and simplification in the process of internal data processing are studied.On this basis,a method of creating a three-dimensional model of cultural relic buildings by using three-dimensional point clouds is proposed.A new point cloud processing scheme is designed to solve the problems of too much noise and overlapping point clouds after importing drawing software and finally a BIM model of the building is created.The main work and important conclusions of this paper are as follows:Firstly,RANSAC algorithm is applied to the acquisition of building facade point cloud patches and reasonable patch extraction threshold parameters are selected by comparing patch extraction effects under multiple sets of different thresholds.On this basis,an improved RANSAC algorithm is proposed,which is to extract point cloud patches and r-radius patches for denoising,respectively.the reasonable radius value and point threshold are determined through the analysis of an example to meet the processing requirements of efficient patch extraction and effective removal of noise points in patches.Secondly,based on the extraction of point clouds,the extraction algorithm of point clouds on building facade feature lines is studied.The reasonable k-neighborhood range and distance average threshold are determined through the analysis of an example to extract the point cloud on the building facade feature line.In order to obtain the plane information of building components,the point clouds after splicing,denoising and simplification are sliced within a specific height and thickness range.Finally,the point cloud of building facade characteristic line and the point cloud of plane slice are imported into CAD drawing software to depict the twodimensional drawing of the building's plane facade,and the three-dimensional model of the building is created accordingly.In addition,non-geometric information such as building materials,construction time and reinforcement period are added to the modeling process to realize high integration of relevant data of the project to provide complete information for reinforcement and reconstruction of buildings in the later stage.Finally,the feasibility of this research is verified by the application research on the point cloud acquisition and modeling process carried out by "Guangxing Li" inner courtyard,a modern architecture in Qingdao.Under the background of rapid innovation of 3D laser scanning technology,it plays an important role in the acquisition of existing building information.In this paper,the advantages of this technology are applied to the construction of three-dimensional models of buildings to provide reference for the research of digital modeling of modern buildings.