In Zack Snyder’s “Army of the Dead,” premiering May 21 on Netflix, Dave Bautista stars as a mercenary on a mission to retrieve $200 million from the vault of a Las Vegas casino by crossing into a quarantine zone in the middle of a zombie apocalypse.

But the heist turned out to be the easy part when the filmmakers, who needed to shoot key rooftop sequences on the Vegas Strip, were met with hard nos by casino owners. “They wanted nothing to do with us,” says visual effects supervisor Marcus Taormina. Not only could Taormina and his team not access roofs, but they couldn’t get onto the casino properties at all.

The filmmakers decided to shoot in Atlantic City and Albuquerque — but to ensure realism, they needed to devise a digital map of the Vegas skyline that they could then replicate in VFX.

Taormina went to Las Vegas to scout the Strip; he was armed with laser-driven Lidar technology that allowed him to measure spatial relations. He made Lidar scans of several intersections, since sidewalks were public domain. On the way back home to discuss a plan of action with Snyder, he discovered the Phase One camera, designed for aerial photography such as surveying large oil fields.

Popular on Variety

They mapped out a meticulous plan to present to the city that included exactly how long each shot would take, knowing that they would need to shut down intersections while they were filming. The idea was not only to attach the Phase One camera on a helicopter but also to use the Lidar camera at lower levels. “We had a four-foot-by-two-foot map of the Strip that detailed where we wanted to be,” Taormina says.

In the end, Taormina and his team spent 12 days in Vegas capturing scans. “We flew the Phase One at 100 or 200 feet [high] depending on where we were on the Strip, and that got us this great vantage point,” he says. “And we were allowed to fly a drone, and that had never been done before.

“It worked well. I don’t think I’d do anything differently.”