PIXAR STUDIOS, for all its renown for creating highly detailed worlds, has rarely had to worry too much about cultural authenticity. Even after all their fabled research for movies such as “Brave” and “Ratatouille,” the filmmakers have been free to use their imaginations, without real fear of offending toymakers, automakers or entomologists.

The Bay Area studio knew, however, that centering “Coco,” which opens Nov. 22, on Mexico’s Day of the Dead holiday would enter an entirely different realm, because it would include not only depictions of traditions, but also a significant increase in casting diversity.

“We knew from the early stages that in creating this film,” co-director Adrian Molina says, “accompanying it was this huge responsibility to represent it faithfully — to get the culture right — and to be very thoughtful in being stewards of what the celebration is.”

The Day of the Dead, or Día de los Muertos, is celebrated widely by Mexicans and Mexican Americans (as well in some other nations) each autumn in remembrance of departed loved ones and in support of their journey in the hereafter. “Coco” revolves around several generations of relatives, both living and deceased, who have lessons to learn and long-buried family secrets to uncover.

Some filmmakers might have appropriated the holiday as needed, simply grafting customs and rituals onto an existing narrative. That is not at all, however, how Pixar works.

“We didn’t want to backwards-construct the story and then do an overlay of culture on top of it,” says Molina, who is of Mexican descent. “We decided pretty much when the film was greenlit — maybe even before — that we wanted to get the research done early.”

Molina, 32, grew up in Grass Valley, Calif. (just north of Sacramento), seeing some aspects of the holiday, but not others. His Mexican American father was born in Southern California, and his mother was born in Jalisco, Mexico. “Where my mother grew up, they didn’t celebrate Day of the Dead quite like you see in the film. In her town, it leaned more into the tradition of All Saints’ Day and All Souls’ Day,” Molina says, referring to the Christian holidays typically celebrated in the days right after Halloween.

Molina, director Lee Unkrich (“Toy Story 3″), producer Darla Anderson and story supervisor Jason Katz, in working on “Coco” over a half-dozen years, knew they needed to engage Dia de los Muertos fully.

“We wanted to experience the holiday: visit the people, visit the families, ask questions, take photos,” Molina says of the Pixar team’s research field trips to Mexico. “We wanted to really immerse ourselves in what the celebration of the Day of the Dead was. Then we would be ready to start discussing story.”

That animated story revolves around a boy, Miguel (voiced by Anthony Gonzalez), who longs to sing and play the guitar in public, despite a grandmother’s crackdown on making music — a ban that arose out of a distant family secret and still-raw emotional wound. Coco, Miguel’s great grandmother, is the last living link to that long-ago misunderstanding involving her father, a traveling musician.

“Coco” bursts with the holiday’s saturated colors, as well as such Day of the Dead markers as the “ofrenda” (private altar), brightly painted sugar skulls, cut-paper decorations and marigold-strewn paths.

The movie “captures the fact that this is a very heterogeneous, generous festival,” says Gael Garcia Bernal, who voices the troubled ghost Hector.

The filmmakers, in turn, “didn’t impose that ‘this’ is what Day of the Dead is,” adds the Golden Globe-winning Bernal (“Mozart in the Jungle”), who was born in Guadalajara. “They did what a Mexican would do: They brought in [traditions] from Oaxaca, from Guerrero, from Mexico City and different places.”

Yet the element that the filmmakers hope will especially pull in viewers is the theme of family that’s so central to the holiday.

Molina (“Monsters University,” “Ratatouille”) had called his mother the very morning he spoke to a reporter — to wish Mom a happy birthday. He credits living with his grandparents for a time as a source of inspiration for this film, despite the fact they spoke little English, and he wasn’t fluent in Spanish as a boy.

“There’s a certain language to family, and there’s a certain language across generations — whether it’s a literal language, or just the acts of love and duty and responsibility that come with being a family,” Molina says. “Those seemed like the interesting things from my experience that could completely apply to this kid [Miguel] who feels out of place in his family, or who feels like the traditions of his family don’t necessarily make room for who he is as an individual.”

(Molina notes that unlike Miguel, he was very much encouraged to pursue the arts. His parents supported his love of animation that was stoked by watching documentary footage of animation legends as a middle-schooler, and he began a Pixar internship after his junior year at storied Cal Arts.)

Creating a Day of the Dead film also led Pixar — which has featured relatively few characters of colors over the past quarter-century — to hire a nearly all-Latino cast of voice actors, including Benjamin Bratt, Alanna Ubach and Edward James Olmos. “This film has leaned very heavily at the studio on Latino artists,” Molina says, “from the animation side to the story side to the art/visual development side.”

Molina also applauds Pixar’s creative move into specific cultures. “If you’re not willing to engage and tap into the stories of other people, and let them be their most talented selves as artists, as performers, as filmmakers, you’re missing out,” he says. “And you’re missing out on what the audience wants.”

“Everyone wants to hold the memories of the ones that have passed on with joy,” Molina says of “Coco,” “and share those memories, and keep them alive.”

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