3D City Models are virtual representations of urban environments integrating geospatial data like buildings, terrain, landmarks, infrastructure landscapes and vegetation. 3D City Models positively influence urban planning, offer environmental analyses, can help manage risk and leads to better decisionmaking. Due to the rapid change in urban environments, there is a growing need for more efficient methods for spatial data acquisition as well as processing methods, which will meet the needs of 3D City Models in terms of accuracy, details, but also in terms of time and cost.

In this paper methods for spatial data acquisition and data processing are presented, theoretically and practically, in order to obtain 3D Building Models as the most important component of the 3D City Models. The main goal of the paper is to explore the possibilities of modelling 3D buildings by processing point cloud data generated from photos produced by Unmanned Aerial Vehicle (UAV), as one of the most convenient, fast and cheap ways for spatial data acquisition. The practical example presented in this paper, point out the power of this kind of data as an input for obtaining 3D building models.