Our Cultural institutions Page highlights our ongoing support of museums and cultural institutions with free accounts and access to tools. In Cultural Heritage Spotlight, we’ll explore museums and cultural institutions who are using 3D technology to bring new life to their collections. Today’s blog post features CyArk, a nonprofit organization which goal is to capture, archive and share the world’s cultural heritage.
CyArk is a nonprofit organization based in California with the mission to capture, archive and share the world’s cultural heritage before it is lost to natural disaster, destroyed by human aggression or ravaged by the passage of time. The organization has archived over 200 sites spanning 43 countries and all seven continents with an eye towards their perpetual preservation. We shared one of their models from Somaliland which you can view here along with more information on the organization.
The site of Templo Mayor in Mexico city is a unique cross section of Mexico’s long and diverse heritage. Rediscovered in only 1978, the ongoing excavation stands in stark contrast to the modern skyscrapers and baroque cathedrals that surround it.
Templo Mayor or the “Great Temple” was one of the principal Aztec temples in the capital city of Tenochtitlan (roughly equivalent to Mexico City’s historic core). The temple formed part of the sacred precinct, a ceremonially important area, consisting of more than 78 structures. Two shrines were located at the top of the temple and were dedicated to the god of war Huitzilopochtli and to Tlaloc the god of rain and agriculture.
Construction of the first temple began sometime after 1325 and was rebuilt over six times reaching a final height of 50 meters. Spanish conquistadors demolished the Sacred Precinct in 1521, using the stones to build the cathedral located just West of the current excavation. For 457 years the structure lay forgotten beneath modern Mexico City until 1978 when electrical workers digging in the main plaza rediscovered the site.
Although many of the more sensitive artifacts recovered from the site have been removed to the associated museum, the majority of the site remains uncovered and exposed to the elements. As a result of heavy air pollution, acid rain often falls on Mexico City and has irreversibly damaged the sensitive stone artifacts already. Of special concern are nine carved serpent heads and two carved frog figurines that remain in situ and feature original pigmentation, one of which you can explore here.
CyArk worked with the Templo Mayor conservators and staff to scan a selection of their most delicate objects including the frogs and serpents to ensure that there is a record of the collection lest they continue to degrade. This pro-bono project will serve as a baseline to compare future scans to assess the rate of deterioration, as well as serve as the foundation for Templo Mayor’s 3D collections. Those interested in supporting the completion of the Project are encouraged to visit cyark.org/donate to contribute and get involved.
Unlike the previous model we featured from CyArk which utilized terrestrial LiDAR, this little frog was captured using a technology called Structured Light Scanning. The process of modeling from this data is somewhat different due to the way in which the data itself is captured.
Unlike terrestrial LiDAR which emits a single beam of light and then calculates its time of flight, Structured Light Scanning pulses a pattered of gridded LED light over the surface of the object and captures the surface it comes into contact with as a series of individual image frames. These billions of individual frames are then combined in post-processing to yield a single object. The Structured Light Scanned that CyArk uses, the Artec Eva, also has an on-board camera which captures color at the same time as surface geometry, a feature that is still making its way into the latest generation of terrestrial 3D scanners.
The data capture at Templo Mayor was particularly problematic because of the exposed nature of the site. Where Structured Light Scanning works best in low-light scenarios, the team was working in the mid-day sun. This is problematic because sunlight washes out the LED light being emitted, preventing the machine’s sensors from capturing any data.
Thanks again for sharing, Makenna!
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