倾斜摄影三维模型Unreal Engine 4渲染的数据转换方法  

A Data Conversion Method from Oblique Photogrammetric 3D Models to Renderable Assets in Unreal Engine 4

作　　者：张琛 贺彪 郭仁忠 马丁 陈业滨 ZHANG Chen;HE Biao;GUO Renzhong;MA Ding;CHEN Yebin(School of Resource and Environmental Sciences,Wuhan University,Wuhan 430079,China;School of Architecture and Urban Planning,Shenzhen University&Key Laboratory of Urban Natural Resources Monitoring and Simulation,MNR,Shenzhen 518061,China)

机构地区：[1]武汉大学资源与环境科学学院,湖北武汉430079 [2]深圳大学建筑与城市规划学院智慧城市研究院&自然资源部城市自然资源监测与仿真重点实验室,广东深圳518061

出　　处：《武汉大学学报（信息科学版）》2023年第4期514-524,共11页Geomatics and Information Science of Wuhan University

基　　金：国家自然科学基金(41930104)。

摘　　要：对三维地理场景真实还原是数字孪生的核心技术要求之一,地理信息系统与游戏引擎的结合为城市实景三维建设提供了新思路。倾斜摄影数据是实景三维建设中重要的数字底板要素,针对游戏引擎加载倾斜摄影数据问题,以Unreal Engine 4渲染为例提出一种倾斜摄影三维模型数据转换方法。该方法利用原始数据的文件组织,通过数据解析获取转换信息构建数据读取树;迭代树节点时分别对几何数据与纹理数据进行转换,转换过程兼顾游戏引擎渲染资源所需物理属性,最终完成几何和纹理重组。将该方法应用于深圳市福田区倾斜摄影数据,实验结果表明,所提方法能准确实现倾斜摄影三维模型数据至Unreal Engine 4渲染资源的转换,可为类似三维模型数据转换问题提供理论与技术参考。Objectives The digital twin city seeks to restore virtually the geographic scene that is close to reality and provide the audience an immersive experience.Three dimensional(3D)real urban scene is one of the key technologies to achieve the goal.Nowadays,the combination of geographic information system and game engine becomes an industrial trend and provides new opportunities for 3D real urban scene.Oblique photogrammetric data,as being a fundamental data source for 3D urban modeling,is able to represent large-scale and high-precision scene.The game engine plays an excellent role in offering realistic effects and post-production systems that are greatly useful for geospatial data visualization.However,the diversity of specifications and formats of oblique photogrammetric data has caused many different data loading and transformation methods,resulting in a problem to be solved in 3D real urban scene.Methods This paper aims to propose a data transformation approach from oblique photogrammetric data to rendering resources in game engine.To stress,the proposed approach can allow us to load instantly massive amount of oblique photogrammetric data in Unreal Engine,which is one of the most popular game engines.We further compared oblique photogrammetric data with rendering resources in game engine and discussed the significance of such a data transformation.The approach reorganizes the original structure of the data by parsing data into a tree structure that better suits transformation purposes.Also,the proposed approach transforms respectively the geometry and texture data when iterating tree nodes,as well as considers the essential physical properties of rendering assets.All these features are combined into a package data format.Results In the case study of Futian district,Shenzhen,the results show that the proposed approach successfully converts oblique photogrammetric data to rendering resources in Unreal Engine 4.In the transformation process,the geometrical structure and collision properties of triangular mesh are g

关 键 词：倾斜摄影三维模型 Unreal Engine 4 数据转换 城市实景三维 游戏引擎 数字孪生 

分 类 号：P208[天文地球—地图制图学与地理信息工程] P237[天文地球—测绘科学与技术]