Project VERSPERA (2013...)

Since 2013, the Centre de recherche du château de Versailles has been leading a vast operation to digitise some 9,000 graphic documents relating to Versailles (Palace, park, estate, royal administrations and town planning) alongside the Archives nationales, the Bibliothèque nationale de France and the laboratoire ETIS) (Équipes Traitement de l’Information et Systèmes, UMR8051, CY Cergy Paris Université / ENSEA Cergy / CNRS), with the financial support of the Fondation des sciences du patrimoine and the ministère de la Culture. These plans are primarily conserved in the collections of the Archives nationales (7,500 drawings from the collection of the Secretary of State of the Maison du Roi [royal household of the King of France] under the Ancien Régime), but also from the Bibliothèque nationale de France (600 drawings from the Robert De Cotte collection) and from theÉtablissement public du château, du musée et du domaine national de Versailles (200 drawings).

This body of documents, exceptional in terms of its history, its homogeneity and its volume, comprises works primarily drawn up in the offices of the kings’ principle architects, from Louis Le Vau to Richard Mique, and including Jules Hardouin-Mansart, Robert de Cotte and Ange-Jacques Gabriel, all names associated with the excellence of French architecture in the 17^th and 18^th centuries. This corpus is one of the largest collections of public architecture, similar to the Tessin-Cronsdedt-Härleman collections at the Stockholm National museum, and the largest documentary ensemble on classic French palatial in the 17^th and 18^th centuries. This body of work consists of entries from the catalogue set up by Danièle Gallet-Guerne in collaboration with Christian Baulez, Versailles. Dessins d’architecture de la direction générale des Bâtiments du roi, Paris, archives nationales, 1983 and 1989, 2 vol, which have been completed, revised and extended by researchers from the various partner institutions.

The reproduction of this unique corpus in high-quality digital images required extensive restoration works on 750 fragile and precious documents and the introduction of innovative procedures to overcome the technical challenges, mainly relating to dimensions of certain documents and very large format plans (up to 3m x 4m) or the presence of numerous and complex paper annexes. As of 2017, this ambitious operation focusing on making about 16,000 digital images from an exceptional and extremely varied body and of works (general architectural plans, sections, elevations, architectural and decorative details) available to the public via the websites of the various partners. This initiative contributes to the preservation of this unique and fragile collection, which was until now inaccessible.

Alongside the restoration of the plans, their digitisation and the scientific processing of the data, the laboratoire ETIS has developed original 3D modelling software using the original 2D plans of the Palace of Versailles. Its dissemination shall be copyright-free. Once online, the homogeneous and comprehensive nature of the digitised corpus will also facilitate connections and crossovers that would have been previously difficult, or even physically impossible to make, without recourse to new technologies. This will allow us to better understand the distribution, operation and uses of this emblematic royal residence related to its topography. The Palace of Versailles has seen many architectural evolutions since the 17^th century, as a result of the many roles that it successively or simultaneously fulfilled (hunting lodge, a place of entertainment and festivities, the official residence of king and court, historic galleries, or national palace), which today make it impossible to follow the different stages of construction and layout of the Palace. The two-dimensional plans do not allow us to comprehend the complete space, but 3D modelling sheds new light on these unique archives, many of which were hitherto unseen in their current state, thus opening up great potential for our understanding of the previous forms of the Palace, which have often completely disappeared.

The 3D modelling process is based on three main technical stages:

• extraction of 2D data relating to the plans, sections and elevations (geometric shapes, dimensions and scales), using digital image processing tools;
• combining 2D data extracted from different sheets;
• lastly, construction of 3D models.

Although 3D modelling using architects’ plans is commonplace today, a similar task using ancient plans is a “challenge” for digital image processing due to the distinctive characteristics of the documents (symbols are not standardised, straight lines are imprecise, etc.) and their digitisation (creases, occasional watermarks). The VERSPERA software, the algorithms of which rely on the principles of mathematical morphology, thus processes the floor plans almost automatically, so that the structural footprint of the building can be extracted (main walls, partitions or secondary walls), and the staircases located. The use of vertical views, elevations and sections relies more on the intervention of the operator, in order to give some idea of “realism” to the 3D model. The operator selects a vertical face (a wall) to give it the appearance of an elevation; then, the software chooses from this image the area of interest that actually corresponds to the wall. The 3D models produced are edited into a standard format, and can be read on any 3D visualisation application, making it possible to manipulate, “walk around” or “go into” the interior of the model. The VERSPERA software also has a 3D pathway function, which enables a “subjective” video to be created of a journey through the model, based on a route drawn on the floor plan by the operator.

Some parts of the Palace of great historical interest, students at the CY Cergy Paris Université (“Vocational Bachelor’s degree in Multimedia Digital Art and 3D Modelling”) have worked on producing realistic virtual visits of high technical and aesthetic quality.

The VERSPERA software can be applied to any heritage building where there are enough sufficiently precise archive plans to describe the building well, thus opening up infinite possibilities for the valorisation of built heritage in both France and elsewhere.

A research notebook dedicated the project

The research notebook dedicated the project is a communication tool to record the content of the VERSPERA project, how it is moving forward, the work of the various teams and professions called on (academic and technical staff) and to highlight all the contributions and innovations inspired through the collaboration of human sciences and hard sciences.

In particular, you will find the list of partners and people involved in the project as well as the virtual reconstructions carried out as part of the project (in French):

• The small so-called Mignard Gallery (1685…)
• A theater project for Louis XV (1774)
• The Queen’s Nobles salon (current state)
• The temporary Royal Chapel of the Palace of Versailles (1682-1710)
• The Grand Interior Cabinet of Marie Leszczynska (1738)
• An apartment in the Versailles Menagerie
• The decorative projects for Madame Sophie’s library (1769)

Put on line on the CRCV image database

The entire corpus will be put online from 2017 to 2022 via the image database of the CRCV, project leader, and on the sites of the Archives nationales and the Bibliothèque nationale de France for their funds. Heritage Resource is accessible to the international community of researchers and the general public.

An initial part of the body of works Archives nationales concerning the palace and its wings, consisting of 2,220 drawings (i.e. 6,375 images), was published online in December 2017.

Two other migrations of this same collection are scheduled: one concerning the gardens, grounds, Menagerie, Grand and Petit Trianon in 2020, and the other the estate of Versailles (including the water supply works) and the buildings under the control of the Bâtiments du roi Department in the town of Versailles in 2022.

Plans, sections and elevations concerning the palace, the gardens and the town of Versailles taken from the Robert de Cotte and “Topographie“ collections of the Bibliothèque nationale de France were published online in May 2019. They comprise 560 drawings (i.e. 821 images).