AI, Drones And 400,000 Photos Shape Digital Twin Of St. Peter’s Basilica

A sweeping new digital twin of St. Peter’s Basilica, the 400-year-old Vatican City church considered central to Christianity, lets visitors explore the structure’s renowned Renaissance architecture and historic treasures from anywhere in the world without having to board a plane or stand in line.

Scrolling and zooming around a vast interactive website offers up-close, intricately detailed exterior and interior views of the building, from its grand columns to its dome conceived and partially built by Michelangelo. The cupola is more than 450 feet high and ornately decorated with mosaics of heaven, angels, and saints meant to symbolize god’s glory.

Through the website, digital visitors can take immersive 3D tours of significant basilica spaces. Tradition holds that the apostle Peter, an early and influential Christian leader, is buried at the basilica, which took over 120 years to complete atop of a 4th-century church.

Online explorers can walk through the grottoes, an underground labyrinth of chapels and chambers, and the tombs of more than 90 popes, including Pope John Paul II, who died in 2005, as well as royalty like Queen Christina of Sweden. The digital twin even offers glimpses of sights usually hidden from the public due to their height or distance.

The virtual twin is part of larger project called “La Basilica Di San Pietro,” which taps cutting-edge technology to preserve the cherished shrine and deepen understanding of its significance and many relics. The project includes two in-person interactive exhibits, though the digital basilica stands at its center.

“It is literally one of the most technologically advanced and sophisticated projects of its kind that has ever been pursued,” Brad Smith, vice chair and president of Microsoft, a project partner, said at a Vatican press conference on Monday.

Over the course of several weeks, Iconem, a French startup that digitizes cultural heritage sites in 3D, captured over 400,000 high-resolution images of the basilica from multiple angles using cameras, drones and lasers. Data from the images tallied to 22 petabytes — it would take almost 5 million DVDs to record all the data in the image trove, Smith said, and were that many DVDs stacked one on top of the other, they’d extend 3.7 miles.

Artificial intelligence played a key role in bringing St. Peter’s Basilica digital twin to life. Microsoft’s AI for Good Lab, which uses AI to model and create digital representations of physical structures, stitched the photos together into visual landscapes that stretch from the church’s top to bottom and into its remote corners. The company’s AI digital preservation tool identified structural problems, such as missing tiles and cracks and fissures invisible to the naked eye, information that could be used for future preservation efforts.

“Centuries of degradation, combined with the daily influx of over 50,000 visitors, have impacted the Basilica’s structure,” Cardinal Mauro Gambetti, Archpriest of St. Peter’s Basilica, said in a statement. “Changes in temperature and humidity caused by this microclimate have led to subtle deterioration.”

Pope Francis has spoken publicly about the power and potential perils of AI, calling it “both exciting and disorienting.” On Monday, the pope spoke with the team responsible for the basilica’s digital reconstruction and with the Fabbrica di San Pietro, the Vatican institution responsible for maintaining and preserving the landmark.

The pope challenged Fabbrica members to use the latest technologies to care for the basilica in both spiritually and materially. He stressed, however, that their work should not be aimed at promoting tourism but on “investing in new means to tell the faith of the church and the culture it has shaped.”

The St. Peter’s Basilica digital twin launches in the run-up to the Vatican’s Jubilee 2025, a yearlong celebration expected to draw some 32 million pilgrims to Rome.