3D building models using laser scanning: Creating a building information system: The ancient Cathedral of Bergamo

The ability to measure surfaces and objects in their full spatial dimensions is becoming increasingly important for building investigation. Non-contact measurement active scanning techniques, such as laser scanning, are of rapidly increasing importance for the acquisition of three-dimensional models of objects, possibly at the cost of the more traditional passive sensing techniques, in particular photogrammetry. Although speed and process automation are advanced, active devices still demonstrate some operational problems. These may become particularly manifest when the merging of many datasets is attempted during the extraction of effective graphical features from large amounts of information. The authors consider these issues, basing their remarks upon experimental results.