Diving Deep into the Making of Pixar's Luca
Karen Moltenbrey
September 16, 2021

Diving Deep into the Making of Pixar's Luca

We all know someone in our life who pushes us beyond our comfort zone, to try new things, even when that little voice inside our head tells us we can’t or we shouldn’t. 
Enrico Casarosa, director of Disney•Pixar’s Luca, is not one who is afraid to try new things. Casarosa, inspired by his own childhood on the Italian Riviera, challenged the studio’s celebrated masters of the 3D animation domain, to try something different for Pixar’s 24th feature release by incorporating a 2D cartoon aesthetic within Luca’s 3D structure. Indeed, a fish-out-of-water story. In more ways than one.

In Luca, young, shy, introverted, rule-following 13-year-old Luca is befriended by free-spirited teen Alberto, who introduces him to the “finer” things on land, as the two spend an unforgettable summer on the Italian Riviera living a carefree, adventurous life as two young boys should.

However, these two young boys have a big secret: They are actually sea monsters. Above water, they appear human; below the water (or wet), their true nature becomes apparent. Living this double life is risky, as the local human townspeople are often on the lookout for sea monsters after years of reported but unsubstantiated sightings. Despite warnings from his parents, Luca, along with his friend, are determined to enjoy the human world filled with gelato, pasta, scooter rides, and more.

The Vespa-obsessed Alberto has been living above the surface for some time, and his exaggerated knowledge of this unique world impresses his newfound friend. “Alberto literally drags Luca out of the water, and we discover that these sea monsters have the magical ability to transform into human form when they’re dry. The inspiration [for the sea monsters] was sea life, like octopuses, which are able to camouflage and change the way they look,” explains Casarosa, who also had a friend like Alberto who pushed him beyond his comfort zone while growing up in Genoa, a port city on the Italian Riviera. In fact, the character Alberto is inspired by Casarosa’s own childhood friend, also named Alberto.

The film invokes a feeling of nostalgia through its warm, painterly, watercolor style and whimsical animation. While the goal was to give the film a timeless look, the story is set in the late 1950s/early 1960s during the Italian “Golden Age” of cinema and music — a period Casarosa is particularly fond of (despite growing up in the 1980s). And, there are homages to those period movies in the form of posters and signs throughout the CG town.

“The towns [around where I grew up] are stuck in time; they’re so picturesque,” Casarosa says.
The watercolor aesthetic carries with it 2D influences, giving the film a highly stylized look, especially compared to the more realistic CGI typically exhibited in a Pixar film. Looks can be deceiving, however. This is a 3D film, although rather than having everything appear straight, even, and realistic, as computers are tuned to do, the filmmakers wanted Luca to be caricatured and imperfect, so you can feel the hand of the artist.

“The most technically challenging part for us was achieving the visual style that we wanted for this film. It is something that’s very different than what we’ve done in other Pixar movies,” says Character Supervisor Beth Albright.

It might be different compared to the studio’s other features, but the underlying aesthetic is actually an expansion of the look Casarosa used for his coming-of-age short film “La Luna.” Casarosa’s film style is influenced by Japanese animation and artistry. “[For Luca] Enrico would draw these sinuous, simple shapes of reflections in the water that looked like traditional woodblocks,” says Production Designer Daniela Strijleva. “With that in mind, we were challenged with simplifying the look of a 3D film, which was super fun to do, hitting a certain level of caricature that’s true to Enrico’s style. It’s very expressive and lyrical.”

While the film contains a high degree of 2D influence, Casarosa made it clear that he wanted to create something new and different for Luca. “He was very specific that it shouldn’t look like stop-motion, anime, or anything else, and that we had the power of the computer with us, so we could create something new. And that’s something we like to do at Pixar,” says Character Supervisor Sajan Skaria. “While we were inspired by all of that, we had the tools to craft it our way.”

Water Craft
With a film set in a seaside town and with a cast that includes sea creatures, you know there is CG water, and lots of it. Jon Reisch, effects supervisor, recalls looking at the storyboards two years ago and seeing “hundreds and hundreds of shots in Luca that involved water” — the sea in the background, the Portorosso harbor, the boys splashing in and out of the water, and more.
While Pixar’s tool set has become better and better at capturing realism when it comes to water, for this film, the focus was on stylization and playfulness, thus requiring the team to push their tools in a totally different direction in order to achieve more controllable and designable water.

First, they focused on the color of the water, with all the beautiful blues and greens, driven through volumetrics underneath the surface. The goal was to make this water feel like it is from the Mediterranean as opposed to some tropical setting. “Volumetrics is one of the cornerstone building blocks we use in the effects department, typically for clouds, smoke, or explosions. But it turns out that the way light interacts with the water when it passes through the volume of the water in the Mediterranean Sea and in the ocean, it scatters and has similar properties to the way the light scatters around in a cloud,” explains Reisch.

Second, the effects department pushed the stylization of the ocean surface and that of the splashes — and married those two worlds together. While Pixar has tackled water before, for this film the artists used a different system than they did on Finding Dory, requiring a good deal of back-and-forth work with the RenderMan team to figure out a way to seamlessly blend at render time the procedural stylized ocean that is mostly seen on-screen with the simulated areas of splashes by the characters.

Artists needed control over the sculptural shapes that would be injected into their splash simulations. To this end, Pixar reworked some of its tools, giving individual artist control over certain bands of frequency in the water sims by allowing them to dial the high-frequency detail up or down. “It was about challenging what our own preconceptions were about how we would approach that work and using the tools we had in a slightly new way to push into that more simplified, stylized, almost storybook look,” says Reisch.

Most of the effects work, including the cartoon water splashes, was done using SideFX’s Houdini, with the Houdini FLIP simulator at the core. The ocean, meanwhile, was shaded with RenderMan and OSL, then rendered in Foundry’s Katana. Custom nodes were used to generate the initial spectrum of ocean waves.

Over the Land and Under the Sea
It’s clear that Luca, with its unique style, is somewhat atypical for Pixar. Then again, what really is “typical” for a studio that is constantly pushing new boundaries?

A phrase we often hear in the film is “Silencio, Bruno,” a phrase turned by Alberto (and then by Luca) as a way of ignoring that little voice that tells you, “No, you can’t,” and holds you back. Thank goodness Casarosa and the Pixar team hushed that little voice when creating this very special film. Grazie. 

Karen Moltenbrey is the chief editor of CGW.