Using EGS technology, the University of Bologna carried out a survey of the Colonna dei Francesi, a historical monument.
3D technology is now widespread in the cultural heritage field and represents a new tool which supports archaeological research, protection and monitoring of cultural goods. The use of 3D scanners makes it possible to obtain more accurate and detailed information and to shorten work and study time, highlighting how technology supports history. Having 3D digital models facilitates: – the enhancement and promotion of goods, for example by multimedia applications in museums; – the improvement of the cataloguing, study, preservation, planning and restoration simulation process, stability analysis and monitoring of structures susceptible to deterioration, virtual reconstruction of parts, production of copies of the original. Each cultural good is a specific case and has its own characteristics and problems. For this reason, the digital tools are beneficial and effective because they are able to accurately represent the features of shape and color of a three-dimensional object. These tools are becoming increasingly important in this field.
The case examined here is the survey of the so-called “Colonna dei Francesi”, carried out in 2012 by the Department of Civil, Chemical, Environmental and Materials Engineering of the University of Bologna to celebrate the 500th anniversary of the battle that took place in Ravenna in 1512 between the Spanish and Papal troops on one side and the French troops of Gaston de Foix on the other one. The battle is commemorated by the Column, located in Madonna dell’Albero, near Ravenna, that is a massive square-based pillar made of Istrian stone, decorated with fine candelabra arabesques bas-relief, in which ovals, describing the battle and the sack of the city, are inserted. Different techniques were integrated in this work: topographic, photogrammetric and 3D scanning. The University of Bologna put the scanning process into the hands of EGS, that studied the solution including the Artec MHT 3D scanner, combined with the Leios software. Artec scanner is designed to work without contact and to obtain scans of great accuracy in a simple and fast way.
The process of creating 3D digital model starts with the acquisition of partial scans of the object from multiple points of view. The captured data can be directly downloaded to a PC and immediately viewed and edited with the Leios software, which is a fast, reliable and easy to use solution, specially designed by EGS for the processing of 3D scans, editing meshes and reverse engineering. In this phase the data can be subjected to various operations: inspection, cleaning off any wrong points, thinning and melting. The point clouds obtained from the different scans overlap and merge into a single model. The modeling operation starts with the transformation of the point clouds into a continuous surface, the 3D model, generating meshes. In the case of complex objects, such as this one, the modeling time increases because of the large amount of details. The 3D model provides a very detailed description of the object, from which you can obtain accurate metric information. The Column, as you can notice, has a lot of decorated parts and the scanner has been a very effective tool to survey the details.
The activity was developed through a collaboration with the Department of Architecture and Regional Planning, with the coordination of the School of Advanced Studies on the City and the Territory and the involvement of the Center of Industrial Study – Building and Construction, Unit of Recovery and Restoration; promoter was the Cultural Association “La Colonna” with the financing of Unicredit. Analyzing this case, it has been deduced that the advantage in the use of 3D technology lies in the fact of being able to analyze and obtain more detailed information and in a shorter time, compared to those obtained with traditional survey. In fact, these methods involve not only a fast data acquisition but also a brief post-processing. Digital tools, accurate reproducers of the characteristics of three-dimensional objects, are now essential in the field of study, research and preservation of cultural heritage.
