Are point cloud comparisons implemented in standard software suitable for the analysis of area-based deformations of buildings? A case study based on laser scans of a wooden plate and a water dam

For analyzing area-based deformations of buildings based on terrestrial laser scans, several methods exist. If there is no information about the object's geometry, the deformations are analyzed in most cases based on point cloud differences revealed by scanning in two epochs. The point clouds are either compared directly, are previously meshed or they are filtered based on geometric conditions. Standard software packages include these methods. After a theoretical introduction of these point cloud comparisons, they are analyzed based on two examples: the shape deformation and the rigid body movement of a wooden plate and the shape deformation of a water dam. It is revealed that the methods are suited to analyze shape deformations and rigid body movements under certain restrictions. However, more important is the direction of deformation related to the observed surface: out-of-plane deformations are better detectable than in-plane ones. In all cases, the interpretation is only based on inspecting color-coded point cloud differences; a statistical test judging the differences between two epochs is not performed.