Researchon Digital Modeling Technologyof City Basedon Lidar

As a new urban measurement technology,the vehicle LIDAR technology provides a new way to reconstruct the lifelike building 3D model.Based on the study of the principle of vehicle LIDAR on ground location,the characteristics of point cloud data and the modeling methods of various types of LIDAR buildings,this paper determines the modeling scheme of vehicle LIDAR building.Firstly,according to the characteristics of urban point cloud data,a new point cloud filtering method based on gradient difference is proposed.The efficiency and practicability of the method are verified by comparing experiments.In addition,the parameter thresholds are set and the facade of the building is segmented by the random sampling consistency algorithm.The influence of the distance threshold setting on the processing results is analyzed experimentally.Then,the feature extraction of building contours is completed by improving the method of building exterior contour extraction based on semantic recognition and building interior contour extraction based on density of projection points.At last,we use the extracted building contours to combine the topological relations of the patches,construct the geometry frame of the building and write the characteristicdata into DXFwhichimportedintoAutoCAD.Soit generates themodelautomaticallyanduses3 DMAXsoftwaretotexturethereconstructedbuildingmodel texturemaking it more vivid.This paper is based on the original point cloud data acquired by the vehicle LIDAR system and digital modeling of urban buildings is the main research content.The cloud point cloud data filtering,building facade cloud segmentation,building facade profile Extraction and building modeling,and some progress have been studied further in algorithms and theory,which provides a reliable theoretical basis for urban digital modeling,and has certain reference value.