Quick textured mesh generation in Cultural Heritage digitization

The goal of the 3D Icons project, funded under the European Commission’s ICT Policy Support Program which builds on the results of CARARE1 and 3D-COFORM2, is to provide Europeana with 3D models of architectural and archaeological monuments of remarkable cultural importance. The project will end in February 2015, bringing together 16 partners from across Europe (11 countries) with relevant expertise in 3D modeling and digitization. The main purpose of this project is to produce around 4000 accurate 3D models that have also to be generated in simplifi ed form in order to be visualized on lowend personal computers and on the web. To reach this goal a suitable workflow of surveying and modeling has to be outlined. Politecnico di Milano (POLIMI) is one of the partners of the 3D-ICONS project and its goal within the project is to digitize archaeological items belonging to the Civic Archaeological Museum of Milan (MAM). Milan has been capital of the Western Roman Empire for more than one century (from 286 to 402 A.D.) and even if the modern city grew covering strata of historical remains, several signs of the past are still visible. The MAM museum has been built on the remains of the Roman circus, dated back to the IV century A.D., and of the city walls, two towers of which are still visible as well as some remains of Roman houses. The Museum holds more than 1000 archaeological objects related to different historical periods (Greek, Etruscan, Roman, Medieval) organized in thematic rooms for each historical period and grouped by artifact typology: epigraphs, statues, mosaics, furniture and pottery, with very important pieces as the glass cup called Diatreta (only one intact piece left in the world) and a silver plate called the Patera di Parabiago. The research group selected 527 items to be digitally acquired and modeled. Starting from the need to produce this huge amount of models in a quite short period, the use of laser scanning was limited due to the following reasons: i) the artifacts material (marble, glass, bronze etc.) resulted less optically cooperative with laser than with digital photography; ii) the highly texturized surfaces of some archaeological objects may generate signifi cant 3D distortions with triangulation laser scanners (i.e. the most suitable for small volumes); iii) the generation of a texturized mesh model has been demonstrated to be far more time consuming with an active device and texturing it with photos, rather than with SFM. In this paper the solutions of problems occurred during the survey and modeling of the archaeological objects are described. Three case studies, each based on objects different in shape, material and measures are presented.