Visualization of regional seismic response based on oblique photography and point cloud data

Abstract

Efficient and realistic visualization of regional seismic response is of great significance for risk education and emergency response. This study proposes an efficient visualization framework for seismic response of regional buildings, which consists of three parts: (1) oblique photography-based three-dimensional (3D) point cloud modelling of regional buildings; (2) time-history response analysis of regional buildings; and (3) hybrid processing for dynamic visualization. Specifically, the unmanned aerial vehicle (UAV) is adopted for oblique photography. The building coordinate extraction with the least square method and point cloud data segmentation with the clustering algorithm are implemented for the pre-processing. The simplified multi-degree-of-freedom (MDOF) model is developed for the time-history displacement analysis of buildings. Then, the MDOF model is used to match the point cloud model of the buildings for visualization. Preset rendering parameters and dynamic geometrical updating are used to further improve the visualization quality. Taking the Southeast University Jiulonghu campus in Nanjing, China for example, a case study is conducted to validate the feasibility of the developed framework.