How footage of a real storm was combined with the magic of VFX

Snow worked as a digital effects artist twisterhe hoped to try again to create the violent air clouds that devastated all of Oklahoma in the 1996 film.

“Back then, the toolkit was evolving so quickly that I wish I could go back and do it again because technology was evolving so quickly,” says Snow (yes, that’s his real name). The Hollywood Reporter.

Nearly 30 years later, Snow was given the chance to serve as visual effects supervisor for this year’s standalone sequel Twistersstarring Daisy Edgar-Jones and Glen Powell. This time, the challenge was not technological limitations, but audience expectations. “Ultimately, it has to convince an audience that has a much better visual awareness of what tornadoes look like now than they did when they saw the original film,” Snow says of the special effects. “That was what we were going to do.”

Six tornadoes were officially created for the film, although the simulation of the final storm, which erupts after hitting the oil refinery, was so complex that it had to be broken down into smaller iterations, bringing the total to 10. Grounding Tornadoes In fact, director Lee Isaac Chang, Snow says, director Lee Isaac Chong’s primary mission, says Snow, amid the film’s intense action and giving each individual character The VFX the team consulted with meteorologists to ensure their modeling tools were scientifically accurate and powerful enough to capture the complexity of different types of storms, from wide wedge-shaped tornadoes to narrow cones. Using the 3D animation application Houdini, computational fluid dynamics software and proprietary tools from VFX studio Industrial Light & Magic, the team was able to simulate air movement, temperature, buoyancy, gravity, moisture density, vapor dispersion and other elements that define a storm . appearance.

The VFX team also did some research on the ground. “We sent a team of storm chasers with video cameras to photograph the storms. They actually got a couple of tornadoes on film. Unfortunately, there is nothing in the film, but we were able to use some of the storm clouds as footage,” says Snow. “It was great for our visual effects team because you could examine the details with high-quality, high-resolution footage — much better than what you might see on YouTube, for example. This allowed us to make (tornadoes) very realistic. That was our slogan.”

Filming in Oklahoma, in an area known as Tornado Alley (and where the film is set), was a “mixed blessing,” says Snow, explaining how frequent storms of all kinds often brought filming to a halt. “At one point we were shooting a scene at the farmers market near the end of the movie and a big storm came and destroyed the set. The irony was that we were going to demolish the set in the movie, so we had to rebuild this demolished set that was destroyed by hail and then demolish it again.”

On the other hand, the location made it possible to get a certain practical effect. “The good thing was that everyone could experience what the weather was like,” Snow says. “The electricity in the air that you feel in those big storms — that was good for the actors, too. Scott Fisher’s special effects team on set had jet engines, raindrops, hail generators, everything you could imagine (to recreate the environment).”

Like the unpredictability of weather, even the best storm calculations cannot guarantee an accurate result. “There’s also an element of randomness because you’re simulating things with math and you don’t really know how it’s going to turn out. So when you work with those tools to get that spark, there’s this crazy magic,” Snow says. “There are happy occasions, just like when we’re shooting live action.”

The need to control the behavior of storms in the same way as the actors in a movie is why, even with the rapid development of technology, Snow does not see a world where artificial intelligence replaces the human touch in franchises like this one.

“One thing that hasn’t changed between the original movie and this movie is that you have to be able to artistically direct things,” Snow says. “(Technology) has to serve the story, and what helps make things real and beautiful and what makes them appealing to an audience is the artistry. And that aspect, I think, will be there even in 30 years. If not, I don’t know if you want to go see a movie.’

This story first appeared in the January separate issue of The Hollywood Reporter. To get the magazine, click here to subscribe.