顾及局部特征的城市三维模型多尺度表达方法  

Multi-scale Expression Method for Urban 3D Model Considering Local Features

作　　者：霍亮 段元晶[1] 朱翊 沈涛[1,2] 张孝勇 翟佳磊[1] 符季颖 HUO Liang;DUAN Yuanjing;ZHU Yi;SHEN Tao;ZHANG Xiaoyong;ZHAI Jialei;FU Jiying(School of Geomatics and Urban Spatial Information,Beijing University of Civil Engineering and Architecture,Beijing 100044,China;Beijing Advanced Innovation Center for Future Urban Design,Beijing University of Civil Engineering and Architecture,Beijing 102616,China;Chinese Academy of Surveying and Mapping,Beijing 100036,China)

机构地区：[1]北京建筑大学测绘与城市空间信息学院,北京100044 [2]北京建筑大学北京未来城市设计高精尖创新中心,北京102616 [3]中国测绘科学研究院,北京100036

出　　处：《武汉大学学报（信息科学版）》2020年第8期1282-1287,共6页Geomatics and Information Science of Wuhan University

基　　金：国家重点研发计划(2016YFC0803108);北京建筑大学未来城市设计高精尖创新中心重大项目(UDC2018031321)。

摘　　要：当前,城市三维模型在可视化过程中多使用渐进式传输方法,在多尺度表达时会出现局部特征表达不突出、绘制相对延后、用户有效等待时间较长等问题。从多尺度不规则三角网(triangulated irregular network,TIN)建模、局部特征度评价、多尺度表达3个方面开展研究,提出了顾及局部特征的城市三维模型多尺度表达方法,实现了城市三维模型多尺度快速加载。首先,将城市三维模型数据分层分块地进行多尺度TIN建模;然后,在多尺度层次下构建局部特征度评价模型;最后,优先加载传输局部特征度高的细节数据,甚至跨层级表达,从而实现多尺度表达。实践结果表明,该方法可切实优化并提升城市三维模型加载传输的效率。Objectives:In the study of current city 3 D model loading methods,large-scale scenes and single models have not been combined,lack of multi-scale constraints,resulting in the lack of some important information.Therefore,how to make full use of multi-scale spatial data for transmission,expression and provide a flexible and good user experience is the current problem that needs to be considered.Methods:From the three aspects of multi-scale TIN(triangulated irregular network)modeling,local feature evaluation,and multi-scale expression,research was carried out,and a multi-scale expression method of urban 3 D model that took into account local characteristics was proposed,which realized the multi-scale rapid loading of urban 3 D model.First,multi-scale TIN modeling is performed on the citys three-dimensional model data in layers;then,the local feature evaluation model is constructed at the multi-scale level;finally,priority is given to loading and transmitting detailed data with high local features,even cross-level expression to achieve multi-scale expression.Results:It can be seen from the realization effect that local areas with high density of linear feature 3 D models are preferentially loaded at the macro scale,models with large volume of the bounding box are preferentially loaded at the meso scale,and local areas with strong identification and high importance are preferentially loaded at the micro scale.The frame rate is used as a reference indicator to compare and analyze this method with the traditional method.The frame rate is maintained at 60 frames per second.It can be seen that the multi-scale constraint of this method makes the loading fluency optimized and the user experience improved.Conclusions:The model is divided into layers to construct a multi-scale TIN model.Based on spatial cognition,a local feature degree evaluation model is constructed based on the local area data of each layer sequence loading solves the problem that the drawing of local feature data in the progressive transmission method of t

关 键 词：城市三维模型 多尺度TIN建模 局部特征 细节层次 多尺度表达 

分 类 号：P208[天文地球—地图制图学与地理信息工程]