Geometric versus Texture Detail in 3-D Models of Real World Buildings

The creation of three-dimensional CAD models of real world objects and their rendering using photorealistic texture are current topics of investigation. In the case of buildings and other objects of urban environments the need for this technology is evident from various applications. The primary source material consists of images which serve for both the reconstruction of the object’s geometry and the creation of texture.Depending on the scale of the digital source images and on the specifics of an application one may require more or less detail of the geometry. The use of photorealistic texture enhances the perceived detail even in the absence of a detailed geometric model; however one needs to overcome correspondence problems between texture and geometry, which partly may be caused by issues of illumination.We present in this paper a progress report on one aspect of urban models, namely the reconstruction of roofs. To improve the automation of datacollection we propose the fusion of digital map data and aerial images. We discuss an affine matching procedure. In addition we illustrate the correspondence problem between geometry and photo-texture.Our initial experiences are based on results from two test sites, one in Vienna and the other in the city of Graz.