Automatic Generation System for 3-D Urban Model by the Integration of GIS and Computer Vision

基于数字地图上的建筑物等高线（建筑物多边形）和道路折线等特征，提出了自动生成三维城市模型的系统。三维城市模型是一种重要的信息基础设施，可用于景观评估、城市规划、灾害预防模拟、旅游和许多其他商业实践等多个领域。此外，向公众公开公共项目信息，鼓励公众参与城市规划，这是一个新的应用领域，三维城市模型可以发挥很大的作用。当一个真实的城市世界被投射到三维虚拟空间时，建筑是这个空间中的主要对象。为了实现三维城市模型，高效地生成建筑模型至关重要。然而，为了实现三维建筑模型，需要耗费大量的时间和人力来获取空间数据和设计模型。举个例子，当你用CSG手工建模一个有屋顶的房子时，你必须遵循这些费力的建模步骤：1)生成合适大小的原语，比如方框、棱镜或多面体，它们将构成房子的一部分；2)在这些原语之间进行布尔运算，形成屋顶和房屋的形状；3)房屋部分的旋转；4)房屋部分的定位；5)将纹理映射到这些部分上。为了使上述步骤自动化，我们提出了GIS和CG集成系统，该系统可以从GIS存储的数字地图上的建筑多边形自动生成三维建筑模型。大多数建筑多边形都有直角（正交多边形），并且顶点的数量不同。提出了一种将正交多边形划分为矩形集的算法。划分后，集成系统将CG原语即建筑部件放置在这些多边形上，形成三维建筑模型。该系统自动生成三维城市模型的速度非常快，可以满足实现另一种替代方案的迫切需求。在此基础上，提出了以GIS存储和控制的水道中心线为中心生成三维水道模型的自动生成系统。恢复自然栖息地和自然曲径的水道对城市的复兴起着重要的作用。水道改善工程旨在提供稳定、可维护的防洪，同时在环境上恢复水道的自然曲径，并在水道沿线增加设施和娱乐机会。在这些项目中，三维水道模型将作为规划或提议的市民、社区、设计师和官员的共同形象。然而，为了实现三维水道模型，需要耗费大量的时间和人力来设计河岸、海岸、植被和地形特征。在我们的研究中，我们开发了一个系统来自动生成三维水道模型，将GIS和CG相结合。少

Based on features on digital map, such as building contour (building polygon) and road polyline, we are proposing the system to generate 3-D Urban Model automatically. A 3-D urban model is an important information infrastructure that can be utilized in, several fields, such as landscape evaluation, urban planning, disaster prevention simulation, tourism, and many other business practices. In addition, disclosure of information about public projects to the public in order to encourage their participation in city planning is a new application area where a 3-D urban model can be of great use. When a real urban world is projected into 3-D virtual space, buildings are major objects in this space. To realize a 3-D urban model, it is important to generate building models efficiently. However, in order to realize 3-D building models, enormous time and labor has to be consumed to acquire the spatial data and to design the models. For example, when manually modeling a house with roofs by Constru … More ctive Solid Geometry (CSG), one must follow these laborious modeling steps : 1)generation of primitives of appropriate size, such as box, prism or polyhedron that will form parts of a house 2)boolean operation among these primitives to form the shapes of a roof and a house body 3)rotation of parts of a house 4)positioning of parts of a house 5)texture mapping onto these parts.In order to automate the steps mentioned above, we proposed the GIS and CG integrated system that automatically generates 3-D building models from building polygons on a digital map stored by GIS. Most building polygons have right angles (orthogonal polygon) and varies in the number of the vertices. The algorithm for dividing orthogonal polygon into a set of rectangles is developed. After dividing, the integrated system is placing CG primitives i.e. building parts on these polygons to form a 3-D building model. The system automatically generates a 3-D urban model so quickly that it meets the urgent demand to realize another alternative plan.Also, we propose the automatic generation system to produce 3-D water way model from a center line of water way stored and controlled by GIS. The water way that restores native habitat and its natural meander plays an important role for the revitalization of a city. The water way improvements project aims to provide stable, maintainable flood control while environmentally restoring sections of water way to their natural meanders and adding amenities and recreational opportunities along the water way. In these projects, 3-D water way model will serve as planned or proposed common image among citizen, neighborhood, designers and officials. However, in order to realize 3-D water way model, enormous time and labor have to be consumed to design bank, shore, vegetation and topographical features. In our research, we developed the system to generate 3-D water way models, automatically by integrating GIS and CG. Less