Abstract: Aiming at the problem of urban redevelopment in modernization construction, traditional measurement methods are not only low in measurement efficiency, but also cannot accurately obtain all the information of the building facade for buildings with complex structures. There are incomplete measurement and low modeling efficiency. This article first uses 3D laser scanning technology to obtain massive point cloud data, which contains all the 3D information of the building; then uses multiple modeling platforms to work together, combined with real photos, to perform 3D reconstruction of complex buildings to obtain facades of the target building in all directions; compared and analyzed the model data with the field point cloud data and the actual building height, which can not only obtain accurate quickly, true and comprehensive facade information of the building, but also improve work efficiency and provide detailed and reliable information for the construction and planning of smart cities.

Key words: 3D laser scanning technology, urban redevelopment, 3D reconstruction, facade extraction