Digital documentation of complex architectures by integration of multiple techniques – The case study of Valer Castle

The digital documentation of monuments and architectures is an important field of application of the 3D modeling where both visual quality and precise 3D measurement are important. This paper proposes an integrated approach based upon the combination of different 3D modeling techniques for the virtual reconstruction of complex architectures like those found in medieval castles. The need of combining multiple techniques, like terrestrial laser scanning, photogrammetry and digital surveying comes from the complexity of some structures and by the lack of a single technique capable of giving satisfactory results in all measuring conditions. This paper will address modeling issues related to the automation of photogrammetric methods and to the fusion of 3D models acquired with different techniques, at different point densities and measurement accuracies. The test bench is a medieval castle placed in Trentino A.A., a tiny region in Northern Italy.