Generalization of buildings within the framework of CityGML  

作　　者：Siddique Ullah BAIG Alias ABDUL-RAHMAN 

机构地区：[1]Faculty of Geoinformation Science and Real Estate,Department of Geoinformatics,Universiti Teknologi Malaysia,UTM Skudai 81310,Johor Bahru,Malaysia

出　　处：《Geo-Spatial Information Science》2013年第4期247-255,共9页地球空间信息科学学报（英文）

基　　金：We would like to convey our deepest acknowledgement firstly to Universiti Teknologi Malaysia(UTM)for providing research grant Vote No.Q.J130000.7127.04J81;Last but not least our sincere appreciation to The Research Management Centre(RMC)of UTM and The Ministry of Higher Education(MOHE),Malaysia for enabling us to carry out this research project.

摘　　要：For a better visual impression,3D information systems and architecture need detailed,photo-realistic visualization of 3D data-sets.However,easy accessibility with efficient rendering becomes difficult due to the detailed data associated with 3D objects.Therefore,different applications demand different levels of detail(LoD).Currently,City Geography Markup Language(CityGML),as the Open Geospatial Consortium standard,is being used to model and represent buildings in different LoDs(LoD0–LoD4),but it does not provide methods to generate different LoDs automatically.Thus,generalized(abstracted)3D scenes of buildings need to be generated to fulfill the demands of task-specific applications by reducing data volume.This paper discusses various ways to generalize building models,within the framework of CityGML,reducing the level of detail from higher LoD to lower.The LoD4 data is parsed and analyzed.Various heuristics are applied to simplify the ground plan and the results are then aggregated.The minimum length of an edge for simplification is restricted to the CityGML generalization specifications provided and is characterized by differing accuracies and minimal dimensions of objects for LoD1 and LoD2.This could maintain the accuracy of generalized objects and avoid the elimination or merging of important features.Second,the heights of the walls of the simplified ground plans are raised with the aim to construct simplified 3D building models.Algorithms for simplification and aggregation aiming to derive LoD2 and LoD1 are implemented and tested on a number of buildings of Putrajaya,Malaysia.The experiment results show that the minimum length of edges to be simplified is inversely proportional to the size of generalized models.

关 键 词：CITYGML 3D SIMPLIFICATION AGGREGATION city models 

分 类 号：P20[天文地球—测绘科学与技术]