The Sarcophagus of the Spouses: an installation merging holographic techniques and 3D architectural mapping
For the joint Exhibition "The Etruscans and the Afterlife", VisitLab Cineca developed for the Museum of the History of Bologna an installation devoted to the Sarcophagus of the Spouses, from the National Etruscan Museum of Villa Giulia, in Rome.
Combining holographic techniques, 3D video projection mapping and surround sound, this
production has been developed under the technical supervision of Franz Fischnaller and the direction of Giosuè Boetto Cohen, to create an immersive audiovisual storytelling environment.
The main requirements were:
1) produce a full-scale 3D visualisation;
2) minimise technological barriers between the exhibit and visitors;
3) involve the entire exhibition space in the museum's Sala della Cultura in the storytelling context;
4) make the installation transportable, reproducible and adaptable to other exhibition spaces.
Since autostereoscopic technology is not yet mature, the installation relied upon a custom-made three-sided holographic pyramid (4 meter wide, 3 meter high) and a 3D architectural mapping projection system covering a total area of 360m2. This effect is created by an array of 12 projectors which together generate an image of 9940 x 2935 (WxH) pixels resolution, bringing a huge mapped surface reaching up to 12 meters in height to life.
The production was grounded on a nearly exclusive open source pipeline, mainly based on Blender.
The 3D architectural mapping was realised starting from the photogrammetry of the Museum hall. Data were processed in PhotoScan, hence optimised in MeshLab and Blender, for obtaining the hall in real-scale. Then, always in Blender the 3D model of the hall was opened as a plane, over which to create scenes in 3D mapping with an error of maximum 5 pixels.
The 3D model of the Sarcophagus of the Spouses came from a laser scanner and photogrammetric acquisition campaign carried out by five groups of researchers. Data, after the first elaboration in MeshLab, have been finished in Blender.
For the digital restoration of the sarcophagus we adopted the technique of texture painting available in Blender in order to create 7 steps of textures groups used to differentiate and enhance every phase of the recolouring process.
Every scene that involves the sarcophagus uses a different LOD generated from the full resolution model with Blender decimator modifiers or Meshlab filters.
The holographic show in the pyramid had 3 views (front, left and right) that were rendereded by swapping the 3 cameras into the RenderFarm.
The most complex scene of the installation was the explosion of the 400 pieces of the sarcofagous. It was entirely made with Blender: the model was cut along precise edges, that followed the original fracture lines, comparing the colour of terracotta and every displacement of the high resolution model. After the manual fracturing, solidify was used to create realistic pieces, with rim materials. A complex rigid body world system was created to manage the explosion and the spin rotation of the pieces at a certain time in sync with the orchestral music. Three different files were created to compose the explosion scene: 2 for showing the pieces and shadows to be projected on the walls, the other one for showing the pieces still inside the holographic pyramid before thier moving onto the walls. Every file was the composition of three scenes with the different POV of the central camera for an immersive projection.
The montage of the final video was created with Premiere and the Adobe suite, but during the rendering and fixing phase we noticed that Premiere was not able to run multiple instances, forcing us to re-export the entire ".jpg" sequence, even for a single wrong frame. Hence, we swapped to Blender in this final phase in order to easily manage every problem and complete the total rendering process in time (~16 blender instances = 1 our for the export, achieving a speedup of 10x over Premiere).
Renderings have been sent on our Blender Render Farm, running on a PLX supercomputer.
Blender Render Farm on 2.66a
Antonella Guidazzoli, producer
Giosué Boetto Cohen, director
Franz Fischnaller, technical direction
Alfonsina Russo, Maria Anna De Lucia, Rita Cosentino, archaeological supervision
Silvano Imboden, technical supervisor
Daniele De Luca, Computer Graphics lead artist
Lorenzo Castiello, video editing
Luigi Verri, Francesca Delli Ponti, Giuseppe Barbieri, Antonio Baglivo, 3D modeling
Giovanni Bellavia, 2D graphics
Maria Chiara Liguori, Federico Rossi, Maurizio Quarta, 2D graphics support
Fabio Remondino - Erica Nocerino - Fabio Menna (Fondazione Bruno Kessler); Marco Callieri - Matteo Dellepiane - Roberto Scopigno (CNR-ISTI); Andrea Adami - Emanuel Demetrescu - Eva Pietroni (CNR ITABC); Valentina Albano - Simone Oppici (LEICA); Anna Maria Manferdini - Sofia Gasperoni (Dipartimento Architettura Università di Bologna), laser scanner and photogrammetric campaign
Marco Robino, music score
Giuseppe Sassatelli, Elisabetta Govi, Andrea Gaucci, Giulia Morpurgo, archaeological iconographic research
Some views of the installation taken from the TV documentary "Il viaggio oltre la vita. Gli etruschi e l'aldilà tra capolavori e realtà virtuale"
Sample stills from the installation:
The Sarcophagus of the Spouses at the National Etruscan Museum of Villa Giulia, in Rome
The digital version of the Sarcophagus; wireframe and with textures
The reconstruction of the hall of the Museum of the History of Bologna, in MeshLab
During the installation: 3D achitectural mapping projected on the walls of the Museum of the History of Bologna
The virtual restoration of the Sarcophagus
A still image of the cracking and explosion of the Sarcophagus following the lines of the pieces as found in the XIX century
Animation of the explosion in Blender
The explosion of the Sarcophagus projected over the walls