Parametric Architectural Elements from Point Clouds for HBIS Applications

Abstract

To preserve tangible cultural assets for the future, it is crucial to make sure that the maintenance, repair, and restoration of thesebuildings are of high quality. To ensure proper cultural heritage preservation, highly accurate measurement and modelling methodsare necessary. For this purpose, laser scanner systems are widely used; without any doubt, these systems provide many advantagesover conventional measuring techniques. On the other hand, the scan angle, the distance to the object, the object’s materialcomposition, the atmospheric conditions, as well as obstacles between the scanner and objects, can cause gaps or noise in the pointclouds, making it challenging to manage and interpret the resulting datasets. Thus, extracting the geometries of architectural façadeelements from these point clouds is often tedious and requires a high level of expertise. Projects utilizing Building InformationModelling (BIM) Systems have recently begun in Turkey. Although this technology is generally applied to address the whole lifecycle of new buildings beginning with the design stage, it is necessary to define existing structures in this system. In this context,research-development and practices related to tangible cultural assets are carried out under the name of the Historic BuildingInformation System (HBIS). In our study, we create parametric models that are needed for transferring the cultural assets, whichsubject to deformation over years. A semi-automatic methodology based on the RANSAC algorithm was applied to extract geometryfrom point cloud data that contains noise. The obtained model was transferred to BIM following IFC standards. Şehzade Mosque,built by Mimar Sinan in the 16th century Ottoman Classical Period during the reign of Sultan Suleyman the Magnificent, was chosenas the application area of the study. The architectural elements obtained from the application of the current point clouds werecompared with the existing architectural drawings, and the contributions of the study were evaluated.