Semi-automatic generation of 3-D building model by the integration of CG and GIS

When a real urban world is projected into 3-D virtual space, buildings are major objects in this space. To realize the 3-D urban model by computer graphics (CG), it is important to generate building models efficiently. 3-D urban models are the important information infrastructures that can be utilized in several fields, such as landscape evaluation, city planning, civil engineering, architecture, disaster prevention simulation, etc. In this paper, we propose a system to generate 3-D building models semi-automatically by the integration of CG and GIS. Usually, urban planners design the future layout of a town by drawing a map. So, it is convenient for the urban planner who draws the future map to realize an alternative plan if the map can immediately be converted into a 3-D urban model. The system automatically generates a 3-D urban model so quickly that the system meets the urgent demand to realize another alternative plan.