城市建筑三维实体自动化建模技术集成与实践

Integrated the automated technical methods of 3D entities modeling forurban buildings

城市建筑实体是实景三维中国建设中基础地理实体生产的重要内容之一。针对建筑物体块三维模型,现有基于点云数据的建模算法和软件普遍存在自动化程度低、精细程度不足、规模化生产受限等问题,本文提出了面向城市建筑实体的自动化三维重建方法。首先,采用点云分割实例算法识别独立建筑物点云,自动提取并优化其底面轮廓信息;然后,将点云数据进行精简结构管理,通过欧式聚类获取各个顶面构件点集并映射拟合为多边形,引入底面轮廓作为硬约束条件进行后处理精化与合并;最后,研发实现了城市建筑实体自动化三维重建软件,该软件集成了大规模建模、编辑、可视化及质检等功能。上述关键技术及方法已在宁波、南昌和楚雄3个实景三维建设项目进行了验证。验证结果表明,本文方法支持万级以上建筑物体块三维模型快速重建,且建模速度优于16栋/s,可为实景三维建筑实体的规模化生产建设提供有力支撑。

Urban architectural entities are one of the important elements of basic geographic entity production in the construction of 3D real scene China.For the 3D block models of buildings,the existing modeling algorithms and software based on point cloud data generally suffer from low automation,insufficient refinement,and limited scale production,et al.In this paper,we propose an automated 3D reconstruction method for urban building entities.Firstly,the point cloud of independent buildings is identified using the point cloud segmentation instance algorithm,and the bottom surface contour information of the building is automatically extracted and optimized.Then,the segmented point cloud data is managed as a compact structure,and each top surface component point set is obtained through Euclidean clustering and mapped and fitted into polygons.At the same time,the bottom surface contour is introduced as a hard constraint,and the post-processing refinement and merging of the fitted polygons.Finally,the automated 3D reconstruction software for urban building entities is developed and realized,which integrates the capabilities of large-scale modeling,editing,visualization and quality control.The above key technologies and methods have been verified in three 3D real scene construction projects in Ningbo,Nanchang and Chuxiong.The validation results show that it supports the rapid reconstruction of 3D models of building blocks above 10000 levels,and the modeling speed is better than 16 buildings per second,which can provide strong support for the large-scale production and construction of the building entities of the 3D real scene construction.