Research On Application Of Three-dimensional Reconstruction And Virtual Display Of Ancient Buildings

China has a long history and has a large number of ancient buildings.For thousands of years,these ancient buildings have experienced natural weathering,corrosion and man-made destruction,making their protection work particularly important and urgent.As a basic method to obtain spatial digital information,surveying and mapping technology provides important basic data for all stages of ancient building protection.The application of advanced surveying and mapping technology in the field of ancient buildings can play a role in promoting digital protection and virtual tourism,which has reference significance for related projects.Based on modern surveying and mapping technology,this paper studies the realization of three-dimensional reconstruction and virtual display of ancient buildings,and introduces three-dimensional laser scanning technology,digital photogrammetry technology and virtual reality technology in detail.The fusion method of laser point cloud and UAV image data is studied,and the quality evaluation method of multi-source heterogeneous point cloud registration is explored.To optimize the quality problems of multi-source heterogeneous point cloud data,conduct reverse modeling based on multi-source heterogeneous point cloud data,and then develop a virtual display system based on Unity3 D.The main research contents of this paper are:(1)according to the characteristics of point cloud noise,point cloud noise is divided into pseudo noise,large-scale noise,and small-scale noise.Pseudo-noise is removed using interactive methods.Large-scale noise is removed based on statistical filtering and radius filtering algorithms.The noise is smoothed based on the moving least squares algorithm.In order to improve the data processing speed,the Kd-Tree algorithm is used to establish the point cloud organization structure,and different thresholds and sequences are analyzed and adjusted to achieve the optimization of the algorithm in this paper,and to improve the universality of the point cloud filtering algorithm;(2)The cloud registration form realizes the fusion of laser point cloud and multi-view image data.The quality optimization of multi-source heterogeneous point cloud data is realized through the filtering method based on laser point cloud.The multi-source heterogeneous point cloud data is vectorized based on Autodesk CAD It uses Geomagic to make a triangulation model,and 3ds Max to make a CSG geometric model,and form a realistic and refined model in 3ds Max;(3)using Unity3 D as the platform,using the Microsoft Visual Studio 2010 compiler,and using the C# scripting language to build The Beizhen Gulou virtual display system with GUI,terrain scene creation,sky box,and collision detection as the key technologies,realizes first-person scene roaming and small map navigation functions,and finally released on the PC side,presenting a complete desktop ancient building virtual display system In front of the public.