Phil Tippett lowers a stage light and clips a filter over it with clothespins, wincing as the hot metal singes his fingertips. He’s red-faced and sweaty, and the glare from the bulb transforms his beard and shaggy mane of hair into a glowing white nimbus. He raises the light back into position and aims it at his miniature film set, a rusted-out industrial wasteland that’s just a few feet wide.

It’s the middle of a Saturday afternoon, and the 63-year-old Tippett is doing what he typically does on Saturday afternoons: working on his animated film Mad God in his Berkeley studio, using the venerable stop-motion animation technique popularized by Gumby and the Rudolph the Red-Nosed Reindeer holiday special.

Two members of Tippett’s crew are arranging scores of characters on the miniature set as he fine-tunes the lighting. The naked, faceless puppets are about 5 inches tall, and each has screws in its heels allowing it to be anchored in place. Their elongated humanoid bodies are coarse, lumpy, and brown. There’s no getting around it — they look like they’ve been molded out of excrement. They’re supposed to look that way. Tippett calls them “Shit Men.”

These days, people associate stop motion with multiplex fare like The Nightmare Before Christmas, Fantastic Mr. Fox, and ParaNorman, films that may have a macabre streak but still manage to earn a PG rating. Tippett is dismissive of such “cutesy, little kids’ movies.” His project is wordless, free-form, scatological, graphically violent, and aggressively experimental. It will never play in multiplexes, although the first ten-minute installment has screened for genre aficionados at events such as the Sci-Fi X-Fest in the Bay Area and the Telluride Horror Show in Colorado.

Members of the cast of Mad God

The story involves a character called the Assassin who travels to a subterranean realm with the intent of destroying it. Instead, the Assassin is waylaid by the land’s denizens and transmogrified in hideous, unspeakable ways. But the story isn’t the point. The point of Mad God is to use a classic form of animation to create disturbing creatures and unsettling images that have the eerie clarity of a nightmare. “It’s Samuel Beckett meets Tex Avery meets Bosch and Brecht and Buster Keaton,” Tippett says. “And it’s the antithesis of my day job.”

Phil Tippett is one of the most esteemed visual-effects gurus in the American film industry. His namesake company, Tippett Studio, employs around 100 artists and technicians who use cutting-edge computer-generated animation (C.G.) to create the werewolves in the Twilight films, the amphibious demons in Hellboy, and the giant bugs in Starship Troopers. Tippett’s studio can earn millions or even tens of millions of dollars from a single film project. When we met, he was about to fly to Hawaii to the set of the $150 million-plus film Jurassic World to make sure that the live-action footage is shot so it will best accommodate the later addition of digital dinosaurs.

But for Mad God, Tippett relies on a small group of volunteers willing to sacrifice their Saturdays in exchange for a sense of artistic accomplishment and a free lunch. Tippett has run Kickstarter campaigns to cover the cost of supplies and meals. “The first one brought in more than we asked for and allowed us to be a little more ambitious,” he says, gesturing at his miniature set. “Initially, there weren’t going to be as many Shit Men in this scene.”

A full-scale model of RoboCop (including the lower part of actor Peter Weller’s face)

Tippett’s studio workspace is littered with props and miniature models of the cinematic icons that he helped to create. Over in the corner is an Imperial Walker, the quadrupedal troop transporter from The Empire Strikes Back. Hanging on the wall by the coffee machine is a life-size bust of the Reaper vampire from Blade II, with its hideous, gaping maw. Up in the rafters is the gigantic ED-209 kill droid from RoboCop.

The man who helps make photorealistic digital T. rexes come to life in Jurassic World derives a different satisfaction from manipulating his creepy little Shit Men. The side project is his way of playing hooky from the massive animation-industrial complex that he helped create. It’s a way of becoming a bit of a mad god himself, bringing inanimate objects to life with his bare hands, like he used to do before computers took over. “If I’d have had to sit in a room and work at a keyboard all day long, I don’t even think I would’ve gotten into the whole commercial visual-effects racket in the first place,” he has written. Four decades ago, visual effects were created by a small team of skilled craftspeople. These days, they’re often created digitally by thousands of technicians working at a dozen different effects houses around the world.

Tippett’s work on films like Starship Troopers and the original Jurassic Park helped to usher in this new era. But he concedes that the modern production process can be “commodified and homogenized.” In his Berkeley studio on this Saturday afternoon, Tippett is getting back to basics. “Mad God hearkens back to a time when special effects were handmade,” he says. “That forces you to slow down, and it changes how you think. There’s a huge difference when you’re working with real things.”