球体剖分瓦块的大区域真三维地理场景构建

针对目前地理信息科学领域存在的三维地理场景大都是局部的、基于投影的2.5维表面模型的问题,该文提出了利用球体大圆弧八叉树剖分(SGOG)瓦块建立大区域真三维地理场景的方法。将SGOG特定剖分层次的顶点与全球共享DEM数据进行匹配,构建大区域真三维地形框架;以地形起伏度为阈值,采用不同层次的瓦块进行自适应建模,大大减少了数据量;粘贴遥感纹理,建立虚拟地理场景。中国大陆地区的实验结果表明:所提方法不但顾及了地球曲率,克服了投影变形的缺陷,而且可以利用SGOG多尺度特性,灵活建立各种(混合)尺度的模型,并可实现地表上下空间的一体化建模。

Construction of large area true 3D geography scene based on sphere split bricks

Aiming at the problem that the most 3D geographic scene are all local,projection-based and 2.5D surface model which currently exist in the field of geographic information science,this paper proposed a method to build the large area true 3D geographic scene with the sphere geodesic octree grid (SGOG)bricks.This method matched the particular SGOG split-level nodes with the global shared DEM data to build the large area true 3D terrain frame;on this basis,in relief amplitude as a threshold value,it used different split-level bricks adaptively established modeling,and then greatly reducing the amount of data;paste the above model of remote sensing image texture,virtual geography scene was established.Experimental results of mainland China show that the proposed method not only took into account the curvature of the earth to overcome the defects of projection distortion,but also took full advantage of SGOG multi-scale features to flexibly establish of various (or mixed)scale models,as well as to achieve the integration of the upper and lower earth surface space modeling.