NEW YORK, NY.- When “TMNT,” a Teenage Mutant Ninja Turtles animated film, was released in 2007, critic Jeannette Catsoulis wrote in The New York Times that it offered “an impressive lack of visual texture.” She was not wrong. The eponymous reptiles are rendered in an inert computer-generated form, as if they were modeled from plastic and then put on a screen. Their green skin is dull and smooth.

The same cannot be said for the turtles in the latest incarnation of the ooze-filled tale: “Teenage Mutant Ninja Turtles: Mutant Mayhem.” In this new film, released Wednesday, our heroes — Michelangelo, Donatello, Leonardo and Raphael — appear to spring from a (talented) high school doodler’s notebook. Their bodies and faces are rendered with an imperfect sketchy quality that makes their eyes vivid and their smiles vibrant. Their greenness is distinctive and gains extra contours when reflected in New York’s neon lights.

“Mutant Mayhem,” directed by Jeff Rowe, is representative of a larger shift that has occurred in the 16 years since “TMNT” was released. It’s part of a wave of films that proves computer-generated animation doesn’t have to look quite so, well, boring.

So what happened? Well, in 2018, “Spider-Man: Into the Spider-Verse” was released. “Into the Spider-Verse” — along with its even more technically virtuosic sequel, “Across the Spider-Verse” this summer — bucked the trend of modern animation by invoking its hero’s comic-book origins with Ben-Day dots and wild, hallucinogenic sequences.

Since “Into the Spider-Verse” became a box office hit as well as an Oscar winner, major studios have grown less fearful of animation that diverges from the norm. The film proved that audiences wouldn’t reject projects that look markedly different from the house styles of Pixar (“Toy Story”) and DreamWorks (“Shrek”). Films like “Mutant Mayhem,” “The Mitchells vs. The Machines,” “Puss in Boots: The Last Wish” and “Nimona” all have distinctive looks that are visually sensational without conforming to established playbooks.

It’s exciting for the filmmakers, too. “All animators ever did before that was have lunch with each other and bitch about how all animated movies look the same,” Mike Rianda, director of “The Mitchells,” said in an interview. (Rianda is a member of SAG-AFTRA and spoke before the strike.)

Rianda — who worked on that movie alongside Rowe, its co-director — was developing it at Sony Pictures Animation while “Into the Spider-Verse” was in the works. (Both were produced by Phil Lord and Christopher Miller; “The Mitchells” was eventually released on Netflix in 2021.) “The Mitchells,” about a kooky family’s road trip during an AI takeover, looks like a window into the overstimulated mind of its teenage hero, Katie Mitchell (voiced by Abbi Jacobson), an exuberant film geek — and Rianda and Rowe wanted the animation to have all of her quirks. They felt that the humans should look imperfect and asymmetrical rather than like Pixar’s “The Incredibles,” because the plot concerned a battle between Homo sapiens weirdos and regulated robots.

Still, there was pressure from the studio to go the standard route. “That’s easy,” Rianda said. “The computer knows how to do that. It’s already been taught that. It was wonderful to have ‘Spider-Verse’ going on in the next room so we could point to it and say, ‘Look, they’re doing it. We can do it too, right?’”

Films like “Into the Spider-Verse,” and those that have followed in its footsteps, blend animation techniques that are common in 3D computer-generated movies with those that were commonplace in the 2D hand-drawn animation that preceded it. It’s not just that the images are less photorealistic, the movements of the characters are as well. The results are more broadly impressionistic in the ways that Looney Tunes cartoons, Disney classics or decades of anime have been.

For instance, when the cat hero of “Puss in Boots: The Last Wish” sticks his sword into the thumbnail of a giant in the bravura musical opening sequence, the sky goes yellow as the giant gasps with pain. The giant’s thumb turns red, and white lines reverberate in the background mimicking the throbbing.

“The Last Wish,” directed by Joel Crawford, is linked to the era of animation dominated by CGI; it is a spinoff of “Shrek,” a hallmark of that time. For Crawford, “Into the Spider-Verse” showed studios that “audiences were not only accepting of different styles but craved it because you get the same thing over and over.”

Crawford wanted to keep Puss recognizable to fans but put him in the context of a “fairy tale painting.” That meant rendering his fur more as brush strokes rather than strands. Fur is actually a good barometer of the shift. In the 2022 DreamWorks caper “The Bad Guys,” which follows a group of animal criminals, the wolf ringleader’s coat looks like it has been shaped by pen strokes, a change from the way his fuzzier lupine brethren were crafted in Disney’s 2016 comedy “Zootopia.”

But all the animation directors I spoke with argued that the art has to come from a thematically relevant place. For “Nimona,” now on Netflix, directors Troy Quane and Nick Bruno landed on what they described as a “two-and-a-half-D” style that evoked medieval paintings, a fitting look for their graphic-novel adaptation set in a futuristic world with the chivalrous customs of the Middle Ages. A trailer for Disney’s upcoming “Wish” has an illustrated quality in line with its storybook fable plot about a star descending from the sky. The effect is something out of an Arthur Rackham illustration or a Beatrix Potter book mashed up with “Frozen.”

Rowe’s initial goal for “Mutant Mayhem” was just to be as bold as possible, excising any timidity he had felt about pushing boundaries on “The Mitchells.” As he spent more time working on the world of the Turtles, he figured out where those impulses were coming from and how they’d fit into the story. He and the production designer, Yashar Kassai, rediscovered drawings they had done as teenagers. “There’s just this unmitigated expression and honesty to those kinds of drawings,” Rowe said. “It’s a movie about teenagers; that’s our North Star. Let’s commit to the art style looking like it was made by teenagers. Ideally the world and the characters will look like they drew themselves.”

As a viewer, I find it’s invigorating to see the animators on “Mutant Mayhem” quite literally coloring outside the lines. When the turtles jump across rooftops, the moon behind them appears to be vibrating scribbles. You can see (digital) pen lines in explosions and expressions.

“At first ‘Spider-Verse’ gave people permission,” Rowe said. “And now I think with ‘Spider-Verse 2,’ it’s made it a mandate. I think if anyone makes a film that looks like a CG 3D film from the last 30 years now, it’s going to feel dated.” For audiences, that’s great news.

This article originally appeared in The New York Times.