Terrestrial Scanning / Archaeology & Cultural Heritage

D. Visintini, E. Siotto, E. Menean "3D Modeling of St. Anthony Abbot Church in S.Daniele del Friuli (I): From Laser Scanning and Photogrammetry to VRML/X3D Model" 19.10.2009

The paper describes the steps of the 3D modeling of the Church of Saint Anthony Abbot in San Daniele del Friuli (I), from the laser scanning and photogrammetric integrated surveying to the final VRML/X3D photorealistic model. This church keeps the most beautiful and harmonious cycle of Renaissance frescoes of the region, painted by Pellegrino da San Daniele: the virtual model is intended also as an instrument to help visitors or studious to better understand the narration meaning hidden in the fresco episodes.
For the inner and outer surveying of the church, the Riegl Z390I system integrated with a Nikon D200 photogrammetric camera was employed: 18 different point clouds for about 33 millions of points and 163 digital images were automatically collected. Data processing carried out by RiSCAN PRO® software (Riegl) allowed the scan registration, the 3D surface reconstruction and the image texturing with satisfactory results. Particular attentions have been given to the 3D surface of the interior of the church, before in its construction by partial Delaunay triangulations and later in its smoothing and decimation for an efficient management of a 3D model with "few" (hundreds of thousands!) triangles but anyway preserving a high geometric detail. New images have been later acquired with the metric camera without laser scanning system, to substitute the original ones having illumination troubles: these new images have been externally oriented by natural points on the surface and then textured onto it.
The 3D model and the image textures have been imported in the VRML/X3D space, where six thematic tours will be available. The model is structured in different LoD (Levels of Detail) for the model geometry and textures resolution, and each frescoes scene and figure is linked by means an Anchor with the corresponding card of the web Regional Information System of the Cultural Heritage.