3D supported restoration: the Neptune fountain in Bologna

The restoration of the Neptune Fountain in Bologna (Italy) started in 2016 and will be terminated in the first half of 2017. This action is funded by Comune di Bologna and it is joint project of Bologna University, Istituto Superiore per la Conservazione ed il Restauro del MiBACT (ISCR) and CNR-ISTI. This restoration qualifies as a major restoration action both for the complexity of the artwork (a complex multi-material monument, with parts in stone and bronze showing different conservation issues) and the large number of scientific investigation actions planned by the many research and conservation experts involved (belonging to the Univ. of Bologna and ISCR).

We decided to present this action as our contribution to the 2016 FOCUS due to the highly innovative documentation methodology endorsed in this project.

CNR-ISTI has designed and implemented a data archival infrastructure which was in the wish list of ISCR since a few years. The goal of the information system designed for the Neptune case study is an archival and consultation system able to encode and store all related documentation and knowledge on top of the digital 3D model of the artwork. The 3D model becomes the indexing resource for geo-referencing all data, providing all features required to browse over the artwork, access all data and to upload any information token.
The data managed by the system are: information concerning the conservation status of the artwork before the restoration; the results of all scientific diagnostic investigation analysis performed on the monument; all graphic reliefs stating and documenting the conservation condition and the major problems of the monument, created directly by drawing over the digital 3D model; finally, all those data should also be (at least partially) opened to the public, to support dissemination and public awareness.

The information system has been designed in collaboration by University of Bologna (with prof. Marco Gaiani, project coordinator, and his staff), ISCR and CNR-ISTI. CNR-ISTI was in charge of the implementation of the system.

This project is highly innovative since the information system manages the data by mapping (and geo-referencing them) over a high-resolution 3D model of the entire monument; moreover, all data access and navigation/inspection is implemented using web technology, thus the access of expert and ordinary people is by standard web pages and browsers. Conversely, previous restoration information systems were based on a 2D approach and thus requested the curator to first select a projection space and then plan the representation; this led to a dispersed and parcelled representation when the focus was to manage a 3D artwork.

The digital 3D model of the Neptune Fountain was digitized by University of Bologna and Studio MCM, using 3D scanning technologies (both active such as laser scanning and passive, structure from motion). The global model obtained is several hundred million triangles and has high-quality textures mapped over the geometry.
This high-resolution model can be navigated and inspected in real time over the web by using the CNR-ISTI platform "3DHP" ( Users can visualize either the entire 3D monument or some selected portions; to this purpose, the monument has been hierarchically divided is sections, to provide a more efficient navigation and editing.
The user of the information system (restorer, technician, scholar) can analyse the status of the artwork, using any device connected to internet (laptop, tablet). The system obviously is not limited to just the visual analysis: the operator can insert any document (text, PDF, image, graph) and geo-reference it to a specific location of the monument surface; or can produce the graphic layers with details on the degradation analysis by directly drawing regions over the 3D model. All data inserted are stored on a database, that can be easily queried on line.

The future plans are to generalize the work done for the Neptune, designing a standardized and flexible infrastructure to support the restorers in the documentation of any action on a 3D artwork.