Gods in Color: Polychromy in the Ancient World @ the Legion of Honor Museum.

One of my most exciting recent projects was my involvement with the Gods in Color exhibit at the Legion of Honor Museum in San Francisco. I was invited by Curator Renee Dreyfus to projection map a large marble panel from the ancient Parthenon. The museum had in their possession a plaster replica of the approximately 5 foot wide panel, which was “liberated” from Greece under the Ottoman Empire by the Earl of Elgin, who from 1801 to 1812, moved almost half the marble sculpture from the Parthenon to Britain, where they now controversially reside in the British Museum.

Parthenon Panel. Without projection mapping.

A fact not known to all who have grown accustomed to seeing classical sculpture as pure white marble is that all of these sculptures were once actually painted in full color. It is not known exactly how everything appeared but research has revealed the natural pigments that were used and where they were applied to the marble. It is thought likely that the surfaces were finished in rather garish fashion to highlight them from afar.

Parthenon Panel. Projection mapping by Grant Diffendaffer

For the exhibit, I used a painting that was a historical representation done by Rebecca Levitan, as part of a project at Emory University. For my part, I began by photographing the panel to create a digital 3D photogrammetric representation of the panel. For that purpose, I used 250 high res photos, which I processed using Autodesk’s Recap Photo software. From there I used a process that moved back and forth between ZBrush and Photoshop to accurately project the lines of the painting to the surface of the digital model.

My hope was to use this process to correct and align the artwork so that it would accurately display when shown from a single projector onto the surface of the actual plaster panel. This was something that was somewhat easier said than done. While I had hoped to make the actual projection alignment a digital process, using either scanning or photogrammetry, it ended up being a more manual process.  It was still a useful and productive journey for me to pass through that digital space, and it was clear to me that this is a useful projection mapping workflow–one that will get easier as software and hardware options combine to basically let projectors “see” what they are projecting.

Many thanks to all who made the project possible–Renee Dreyfus, Rebecca Levitan, and Rich Rice, as well as the photography department of the DeYoung.