Abstract: With the development of digital city construction, more and more complex large buildings need to complete 3D modeling. For the irregular and complex buildings, the traditional total station data acquisition method is more cumbersome and laborious. In this paper, the ground laser scanner is used to obtain the point cloud data inside and outside a large building, and the close range photogrammetry is used to obtain the orthophoto map of the top of the building. The site photos are taken at the small components, and the point cloud registration, denoising, image processing geometric modeling and texture mapping process are carried.Finally the 3D reconstruction of large buildings is completed, and the key technology is researched in the process.

Key words: 3D laser scanning, 3D modeling, close-range photogrammetry, point cloud registration, denoising filter, texture