The Lost Bus, from Apple Original Films and director Paul Greengrass, was inspired by the real events of the Paradise, CA, fires, which devastated a Northern California community in 2018 when high winds caused power lines to fall and start a series of uncontrollable brush fires.
Matthew McConaughey plays school-bus driver Kevin McKay, who finds himself surrounded by fires during his pickup of 22 elementary-school students and their teacher Mary Ludwig (America Ferrera). Cut off from all communication and with the fire closing in, Kevin pushes his bus to the limit in an attempt to deliver the children to safety.
Charlie Noble served as VFX supervisor on the feature, continuing a relationship with the director that includes past collaboration onThe Bourne Ultimatum and
Captain Phillips. Noble’s career includes 10 years at MPC in London, and then co-founding Dneg back in 1998, going on to ultimately become a freelance VFX supervisor in 2019. In the case of
The Lost Bus, he was given the script months before production began, giving him time to break down its visual effects needs and how it would be broken up among its various contributors.
“The considerations, obviously, when you're shooting a movie where the principal antagonist is nature and is the fire, is to make sure that everything is undertaken as safely as possible, but also getting as much as we could out of photography,” he explains. “Wherever we went, SFX always gave us some real propane flames in-camera, so we knew for each take, what real flames looked like. But then all of those flames were subsequently replaced by CG flames that could blow in the strong winds (and) evolve into smoke and clouds of embers.”
The film’s VFX shot count came in just below 1,500, and a dozen studios served as partners, with ILM, Below, Cinesite, Outpost, Rise and Mist acting as the primary vendors. Noble credits Adrian Spanna with creating detailed animatics that helped to visualize what the shots would require in terms of additional effects elements.
“We did do some previs and it was really valuable, especially when it came to early editorial stuff before we got into doing shots,” Noble recalls. “Adrian (will) quite often go to locations. He'll take lots of location [snapshots] and then do sketches on top of those images so that the animatics really closely resemble what the film is going to be like.”
While visual effects are incorporated throughout the film, Noble points to a specific sequence at the end, when the school bus is racing down a hill and out of a heavily-forested area, just as the fire is about to envelope the vehicle. The scene’s movement and framing was shot practically, though imagery was later replaced with VFX.
“We always aim to shoot something for real,” Noble explains. “So all the shots in the movie had a basis in reality - real photography. Now, sometimes those shots get replaced. And that's particularly the case for that end sequence. Obviously, stunts did drive a bus down a narrow track at speed, and enabled the editor to cut the sequence together with those real shots. But then, obviously, you can't have flames for a mile and a half, and flame-effect lighting. We obviously had as much flame as we could get, as much interactive lighting as we can get, but there's a limit. You just couldn't have lit all that. What we shot was pretty spectacular, but there certainly wasn't as much flame as what we required. So, some of those exterior shots were replaced with all-CG shots, but we're retaining all of the bus animation and all of that ground contact with the wheels, all the cameras, so there's a real basis in reality, which I think is essential. There's just a visceral quality to all of the camera work that you can't expect artists to replicate. That's another reason for going out and shooting it all.”
The scene ends with the bus reaching a clearing at the bottom of the hill, with the raging fire and smoke being left behind.
“That last shot, [coming] out of flames and then we're into sunlit safety, that was always going to be pretty complex because you've got two environments,” Noble explains. “A burnt/burning environment, and then you're coming out into an unburnt environment through a whole load of smoke. That has to be all-CG all the way through into the real environment when you get out on the other side.”
Collectively, Noble says the film incorporates as many as 90 minutes of on-screen effects.