Automatic Generation Of 3-D Building Models From Building Polygons On GIS

When a real urban world is projected into 3-D virtual space, buildings are major objects in this space. To realize a 3-D CG urban model, it is important to generate building models efficiently. 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, etc. However, in order to realize a 3-D urban model, enormous time and labor has to be consumed to acquire the spatial data and to design the models. In this paper, we proposed the GIS and CG integrated system that automatically generates a 3-D building model from building polygons on a digital map stored by GIS. Some building polygons contain noise edges to be filtered out. The algorithm for filtering out noise edges and breaking down complicated polygon into primitive ones is presented. By applying the algorithm, we can get a core polygon with smaller vertices, which then can be broken down into a basic L-shaped polygon and rectangles. After breaking down, the integrated system is placing CG primitives i.e. building parts on these polygons to form a 3-D building model.