中文摘要：

为提高细节层次模型的管理效率,提出一种扩展多细节层次功能的三维R树索引方法,基于全局优化和三维聚类分析建立具有均衡结构的动态三维R树索引,并扩展了三维R树索引结构,在中间节点层次引入细节层次模型信息。设计实现了先自下而上、后自上而下全局搜索的节点选择算法和基于k-medoids聚类算法的节点分裂算法,保证节点尺寸均匀、形状规则以及重叠减少。通过仿真试验,证明本文方法能很大程度地提升多细节层次三维城市模型数据库的空间查询效率。

英文摘要：

Aiming at the critical issues of LOD models organization,an extended dynamic 3D R-tree structure concerned with LODs is presented.In the node-choosing process,a globally-optimising approach is adopted which is first bottom-up then top-down,and that an improved clustering algorithm based on k-medoids is applied to the node-splitting process.This method makes more even node size,more regular node shape,and less node overlap.Furthermore,a method of integrating R-tree and LOD is put forward based on such kind of good R-tree structure.The simulated experimental analysis results approve that this approach improves 3D query performance relative to existing ones and succeeds in integrating LOD models.