AUTOMATIC GENERATION OF 3D BUILDING MODELS BY BUILDING POLYGONS ORTHOGONALIZATION

A 3D city model is important in urban planning and game industries. But, enormous time and labor has to be consumed to create these 3D models. In order to automate laborious steps, a GIS (Geographic Information System) and CG integrated system is proposed for automatically generating 3D building models, based on building polygons on a digital map. Since technicians are drawing these polygons manually with digitizers, depending on aerial photos, not all building polygons are precisely orthogonal. However, creating 3D building models are expected to be orthogonal. When placing a set of boxes as building bodies for creating the buildings, there may be gaps or overlaps between these boxes if building polygons are not precisely orthogonal. In this paper, the new methodology is proposed for rectifying and orthogonalizing the shape of building polygons and generating 3D building models without any gap and overlap.