topographic model meaning in English

位相模式
心理图式

The research status is firstly analysed in this paper . after an analysis and comparing of existing 3dcm , the methods for constructing topographic model , building model , road model , water system model etc . are focused on the discussion . the tin and grid modeling method are applied for topographic model , a layer - combined model based on triangle partition is presented for building model and a independent triangle partition is presented for the other models . all these models are combined to topographic model in the end
本文首先讨论了国内外3dgis理论的研究现状，对已有的三维城市模型进行了分析和比较，着重探讨了三维城市模型中的地形模型、建筑物模型、道路及水系模型、独立地物模型的构造方法，对地形模型采用tin和grid的建模方法，对建筑物总结出了一种基于三角剖分及分层组合方法实现建筑物的模型构造，对道路及水系等地物采用三角形片面剖分实施单独控制，最后融入dem中。