Visual-effects creation is a collaborative process, and its artists are extremely specialized. A worker might spend an entire career just lighting scenes, or adding texture to cloth, or simply simulating water, a complicated task that involves serious physics. The “Tree of Life” scene in which a predatory dinosaur appears to take pity on a wounded dinosaur and spares its life — supposedly meant to represent the moment when altruism first entered the world — was created by a team including, among others, three riggers (who built the dinosaur bodies), 12 animators (who gave the two creatures movement), two lighters, six compositors (who put it all together) and an animation expert, flown in from London to supervise the work being done in Vancouver. That doesn’t even include previsualization (rough sketches planning the scene) or the clay-model dinosaurs, sculpted and painted by a practical-effects company in Los Angeles, that were laser-scanned, sent to Vancouver and used as blueprints. Each puzzle piece — each new movement of a dinosaur’s head or glint of light off water — had to be reviewed in Los Angeles, Vancouver and Austin, assessed and revised as it went up the chain of command to Malick.

This is a far cry from the early days of the field, when Squires remembers laboring with a team of around 70 artists on “Close Encounters.” Now, blockbusters rely on hundreds of visual-effects workers per film: “Life of Pi” employed 500 artists in five cities, and IMDB credits nearly 2,000 people for the effects in James Cameron’s “Avatar.” (WETA, the effects company that led the movie, says the actual number may well be higher.) “Now, you’re a cog,” Squires says; with rare exceptions, the director probably has no idea who any given VFX artist is or what he or she is doing.

Visual-effects workers want American politicians to step up to protect the industry. But this modern work force doesn’t really fit into many of the solutions created for last century’s workers. There have been attempts at unionizing — VFX is one of the few major sectors of the film industry that hasn’t — but now that the market is global, artists are afraid of anything that might drive up labor costs. Daniel Lay, a former visual-effects artist who has become an activist for the industry, once wanted to petition the Commerce Department to add a countervailing duty (essentially a tariff) on visual effects created in subsidized markets, but he couldn’t raise enough support from the industry to pay the legal fees. Even if he could have, the lawyer his advocacy group worked with, David Yocis, admits that it would have been a tricky case to make. First, they would have to persuade the Commerce Department that visual effects constitute “merchandise.” Then they would have to figure out how to impose a duty on a bunch of data transmitted over the internet, a regulatory puzzle no one seems to have figured out how to crack.

It’s worth pointing out that most of the visual-effects artists I spoke to — in Los Angeles, Vancouver, London and elsewhere — say they enjoy the international nature of the work. Bob Wiatr, who worked at Sony Imageworks before moving to Vancouver, remembers that when he was beginning his career in the 1990s in Hollywood, the industry was all “white American males”; now he has colleagues from Mexico, Germany, Australia and South America. “It’s like a whole world in one place,” he says. “There’s always something to learn from someone else.”

Robb Gardner, a lighting technical artist who has worked on films like “Jurassic World” and “Rango,” reminisces about living in a hotel overseas for several months while working on one particularly big film. “Every floor of that hotel had workers from all over the world,” he says. But “they all had families waiting back where they came from,” he added. There’s a nickname for visual-effects workers’ spouses: VFX widows and widowers. Gardner has moved internationally for work six times over nine years and admits that it’s “a huge stress to your personal life.”

David Breaux Jr. still lives in Los Angeles and does work as a character animator for a group of superhero TV shows. The job is based in Burbank, close to home. But Breaux has worked there for two seasons without seeing any indication that he will officially be added to the staff. When I met him at his house one evening last month, he was exploring his options and had recently had two preliminary job interviews: one with a video-game company in Irvine, Calif., and the other with a major VFX company in London, which offered him the chance to work on what promised to be some of the biggest blockbusters of the next few years. “It’s a really scary proposition to leave the country,” he said, sitting on his well-worn couch in front of a brand-new 4K-definition Sony television, the room’s centerpiece. His fiancée sat in the corner listening, fiddling with her necklace. “We’ve spent a lot of years together,” he said, looking around. “People have given us stuff, and we’ve bought stuff.” There were posters from TV shows and movies he worked on, an old “Tron” arcade console, a “Tron” action figure.