基于混合数字高程模型的交叉口立面设计方法

在交叉口立面CAD方法中，传统二维方法不能进行三维可视化设计和空间分析，曲面拟合方法没有统一的应用标准并且求解困难.以CAD和方格网设计等高线法为前提，提出了交叉口的通用几何模型和设计流程，分析了用不规则格网和不规则三角网的混合数字高程模型表达三维设计面的优势和可行性，讨论了建模的原理和步骤，阐明了运用数字高程模型生成等高线和查询高程、坡度、坡向的方法.在AutoCAD平台上，用.net二次开发技术和托管C++语言编程实现了程序功能.试验结果表明，该方法能精确高效地处理各种形式交叉口.

Elevation design method of intersection based on hybrid digital elevation model

In the CAD methods of elevation design method for intersection， the traditional two dimensional method cannot conduct three dimensional visual design and spatial analysis. In addition， the surface fitting method does not have a unified application standard and is difficult to obtain an analytical solution. Using the premise of the method of CAD and grid square to design contour， the general geometric model and design procedure for intersections were proposed. The advantages and feasibility of describing the three dimensional design surface with a hybrid digital elevation model incorporating irregular grid and triangulated irregular network were analyzed. The mechanism and procedure of modeling were discussed. The methods of creating contour and querying elevation，gradient， and exposure using the digital elevation model were clarified. The program function was implemented with.net advanced development techniques and managed C++ language programming based on the AutoCAD platform. The experimental results show that this method can process the design of intersections of various forms accurately and efficiently．