Autun tympanum in 3D for the movie “Revelation”

ContextCapture is able to capture the finest details of buildings, sculptures, bas-reliefs, archaeological sites and excavations, from simple photographs taken on the field. This allows to extend the use of 3D digitization far beyond the current applicability of laser scanning, with the same benefits in terms of preservation, analysis, education and communication.

A perfect illustration is the movie “Révélation” released in 2013, made by the French company on-situ for the city of Autun, about the portal of the Autun Cathedral. The movie covers the history, as well as proposes a detailed interpretation of the portal’s Last Judgment, a masterpiece achieved in the twelfth century, telling its vicissitudes (context, critical fortunes, iconography…), while incorporating the latest scientific studies. The movie includes plenty of 3D animations and fly-throughs, largely based on the accurate 3D modeling of the portal tympanum with ContextCapture, from 1,000+ photographs acquired with a DSLR.

CHALLENGES

  • Automation. The 3D modeling of such a complex and detailed masterpiece was not feasible with traditional, CAD methods. It required a fully automated solution. Moreover, the laser scanning option had been discarded early, because of its prohibitive cost, and of some specific acquisition constraints: high height, protection net over the portal.
  • Accuracy. The digital mockup of the portal had to render all details of the original handcrafted work as well as its actual dimensions and scale. Indeed, the 3D model had to be used for communication as well as for scientific analysis.
  • Speed. The movie project being already scheduled, the 3D reconstruction of the tympanum had a tight deadline.

SOLUTION

  • ContextCapture Center Edition. Acute3D’s high end software solution was the only available standalone solution able to automatically compute the aerial triangulation of over 1,200 photographs, without any prior information on their initial position and orientation, and then reconstruct the entire model in true-3D, in a reasonable time.

METRICS

  • Imagery acquisition: 1000 photos from a Canon 5D Mark II.
  • Reconstruction: 24 hours on a laptop.
  • Accuracy: 1-2 mm on average.

IMPACT

  • Most accurate 3D model of the tympanum, ever. The final 3D model generated by ContextCapture reveals an unmatched accuracy, taking the most of the 1-2mm resolution input photos, and capturing every single detail of this incredibly complex sculpture.
  • A unique movie, about a unique masterpiece. The movie “Révélation” reveals all details of a unique masterpiece and illustrates fragments of History to an amazed XXIst century audience.
on-situ uses ContextCapture for the preservation and promotion of cultural heritage. We successfully digitized the tympanum of Autun Cathedral and, more recently, the relief map of the city of Saint-Omer. The challenge was to successfully render all the subtleties of these masterpieces, in each single detail. Thanks to ContextCapture we automatically generate very accurate 3D models and can refine them through the touch up process. The end result, photorealistic essence, is simply stunning!
Julien Roger, CTO at on-situ

ABOUT ON-SITU

At the crossroads of Art and Technology, on-situ explores all facets of image processing to create new forms of mediation and innovative sensorial applications, at the service of stories and History.