地形TIN中地理实体拓扑关系表达

Topological representation of geographical entities in terrain TIN

传统地形TIN离散、独立的三角形结构限制了空间实体、空间关系的表达能力,分析和操作也比较困难,应用大多限制在可视化、渲染和光照分析等方面。由于不可能通过简单地扩展和改进现有模型来满足TIN中对空间实体关系表达的需求,从面向对象的角度出发,利用单纯剖分理论对TIN进行了实体划分和拓扑建模,使TIN具有了地理对象结构从而能够进行地理实体的表达与分析,建立了对象化不规则三角网(OTIN)与Euler示性数方向模型(EDM),使得TIN不但可以较好地表达地形起伏信息,还具有实体性和对象性,便于进行空间查询与分析。

With discrete and independent triangles, traditional TIN model limits the representation ability of spatial entities and spatial relations, so it is difficult to implement spatial analysis and manipulation among geographical entities and its application is re- stricted within visualization, rendering, illumination, etc. It is impossible to meet the requirement of entity representation and relation analysis only by expanding and improving existing model. Considering object oriented organizing, based on simple partition theories, this paper brought forward a particular idea of topological modeling in TIN, so entity representation and analysis could be put into execution in terrain TIN. In addition, this paper gave an object triangulated irregular network （OTIN） and an euler direction model （ EDM）. Not ouly the hypsography but also the entity could be abundantly represented by this model. Therefore the entity query and analysis become very easy in OTIN.