夏小科, 贾庆仁, 杨泉, 金星, 李军. 一种面向三维WebGIS的空间数据加载优化方法[J]. 武汉大学学报 ( 信息科学版), 2020, 45(12): 1997-2004. DOI: 10.13203/j.whugis20200184
引用本文: 夏小科, 贾庆仁, 杨泉, 金星, 李军. 一种面向三维WebGIS的空间数据加载优化方法[J]. 武汉大学学报 ( 信息科学版), 2020, 45(12): 1997-2004. DOI: 10.13203/j.whugis20200184
XIA Xiaoke, JIA Qingren, YANG Quan, JIN Xing, LI Jun. An Optimization Method of Spatial Data Loading for 3D WebGIS[J]. Geomatics and Information Science of Wuhan University, 2020, 45(12): 1997-2004. DOI: 10.13203/j.whugis20200184
Citation: XIA Xiaoke, JIA Qingren, YANG Quan, JIN Xing, LI Jun. An Optimization Method of Spatial Data Loading for 3D WebGIS[J]. Geomatics and Information Science of Wuhan University, 2020, 45(12): 1997-2004. DOI: 10.13203/j.whugis20200184

一种面向三维WebGIS的空间数据加载优化方法

An Optimization Method of Spatial Data Loading for 3D WebGIS

  • 摘要: 随着用户需求的不断提高和空间数据的不断丰富,同一地理空间范围可包含地形、遥感影像、倾斜摄影测量三维模型等不同类型空间数据,三维WebGIS在同一场景中对不同类型空间数据尚不能实现有效加载。提出了一种面向三维WebGIS的空间数据加载优化方法,对多类型空间数据高效加载进行优化。首先,利用3D Tiles具有规则包围体外形和重叠区域的结构特点,提出一种基于二叉树的多边形快速生长算法对三维模型的外边界进行定位和粗提取;然后,针对粗提取的多边形外边界存在锯齿状凸起的问题,提出一种基于邻近两点的多边形简化方法,对多边形外边界进行裁剪优化,实现三维模型外边界的精确提取;最后,通过判断地图瓦片和地形瓦片数据与三维模型外边界的包含关系,实现对瓦片数据的选择加载。实验表明,当视点高度在300 m以下时,地图瓦片数据加载总量可减少约40%,表明在不影响三维WebGIS可视化效果的前提下,该方法较为明显地提高了系统的数据加载效率。

     

    Abstract: With the continuous improvement of user needs and the continuous enrichment of spatial data, the same geospatial scope includes different types of spatial data such as terrain, remote sensing images, and 3D models of oblique photogrammetry. 3D WebGIS cannot effectively load different types of spatial data in the same scene. This paper proposes a spatial data loading optimization method for 3D WebGIS to optimize the efficient loading of multiple types of spatial data. First, using the structural features of 3D Tiles with regular enclosing volume shapes and overlapping regions, a fast growth algorithm based on binary tree is proposed to locate and extract the outer boundary of 3D model. Then, there were jagged protrusions on the outer boundary of the roughly extracted polygon. In order to solve the problem, a polygon simplification method based on two neighboring points was proposed to optimize the outer boundary of the polygon to achieve accurate extraction of the outer boundary of the 3D model. Finally, by judging the inclusion of map tile and terrain tile data relationship to achieve selective loading of tile data. Experiments show that when the viewpoint height is below 300 meters, the total load of map tile data can be reduced by about 40%, indicating that the optimization method in this paper can significantly improve the data loading efficiency of the system without affecting the visualization of 3D WebGIS.

     

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