Building Reconstruction Using Planar Faces in Very High Density Height Data

The point densities obtained by airborne laser scanner systems are increasing rapidly. When used for the 3D reconstruction of buildings the increasing amounts of points contain more and more information about the shape of buildings. Therefore methods for 3D reconstruction can be more data driven and need less specific object models. In this paper an approach is presented which is based on the detection and outlining of planar faces in dense height data. To avoid loss of information due to interpolation, all operations are performed on the Delaunay triangulation of the original height points. The planes of the faces are determined by clustering of the points. The outlines of the faces are determined by a connected component analysis on the triangles of the Delaunay triangulation. Only a limited amount of generic knowledge is used in the reconstruction. Apart from the assumption that a building can be described by planar faces, it is assumed that there exists a main orientation of the building and that all edges where discontinuities in height occur are either parallel or perpendicular to that orientation. Several results are presented and the pros and cons of the approach are discussed. The conclusion is that building reconstruction from laser altimetry data becomes a strong alternative for semi-automated mapping in images.