3d Building Model Generation from Airborne Laserscanner Data by Straight Line Detection in Specific Orthogonal Projections

The paper describes a novel approach for the generation of 3D building models from airborne laserscanner data, which is based on the detection of straight lines in specific 2D projections of the data. First, the main roof ridge directions of a building are determined. Based on these ridge directions, hypotheses on the roof orientation are generated. The whole point cloud is rotated by the roof orientation and orthogonal projected into a 2D space perpendicular to the roof orientation. Roof edges show up as straight linear point clusters in this 2D projection. These lines representing projections of roof faces are extracted by a line tracing technique. They provide information about inclination and width of the roof faces. Subsequently rotating the points of each roof face around the z-axis and tilting it by its inclination produces another 2D projection containing lines representing the roof face’s length. The technique was tested on a sample of 200 buildings. They were reconstructed with the approach and evaluated for their correctness and geometric accuracy.