Of Mice and Acumen
Issue: Volume 38 Issue 2: (Mar/Apr 2015)

Of Mice and Acumen

Artists at Moving-Picture company give Cinderella a ride

The glass slipper gets all the attention. But where would Cinderella be without her little friends, the family of helpful critters? Four little mice transform into horses and pull Cinderella’s magical golden carriage to the ball. A lizard and a goose become coachmen. And then at midnight, the carriage turns into a pumpkin. The horses become mice again. The coachmen change back into a lizard and a goose.  
It takes skilled artists to transform these characters in a cartoon or storybook. To make the magical characters believable in a live-action film raises the artistic bar. But Disney’s live-action Cinderella has done just that. Critics gave the film rave reviews, praising the retrograde fantasy’s ravishing style, charming magic, and timeless message:  Early in the film, Cinderella’s mother tells her to “have courage and be kind.” She does, and she is. She is to the current crop of warrior princesses in films as the Terminator is to Atticus Finch.

Kenneth Branagh directed the live-action film. Cate Blanchett stars as the evil stepmother, Helena Bonham Carter is the fairy godmother, and Lily James, who was Lady Rose in Downton Abbey, is Cinderella. Charley Henley was the overall visual effects supervisor, and Patrick Ledda was the visual effects supervisor at the Moving-Picture Company (MPC), which brought the CG characters to life.

“Originally we had live mice on set, which we thought we’d use in some shots,” Ledda says. “But, they were chubby mice, and they didn’t do much. They didn’t perform the way the director wanted, so we quickly realized they would be full CG.”

Even so, the animal actors provided good reference for fur and lighting conditions for what became a family of CG mice.

“In Disney’s animated film, the mouse named Gus was chubby and always eating,” Ledda says. “We had the idea he would be the father. We also have a mum who relates a bit to Cinderella, and then two kids. One is more playful and she runs around. The other is more scared. They’re all quite different from each other. We wanted the audience to distinguish them and understand that they belong to a family.”

Toward the end of the project, the MPC crew learned that the mice would talk.

“The director didn’t want them miming,” Ledda says. “So, they have soft speech, but it didn’t really affect our work.”

Mousing Around

MPC has been creating and animating CG characters for many years; their most recent digital characters were Groot and Rocket in The Guardians of the Galaxy, which they created with Framestore. The mice, though, arrived with new challenges for the experienced team.

“We wanted them to be fairly photoreal but with kind of a human form because they interact with Cinderella and understand her,” Ledda says. “We needed a chubby mouse that was big enough to fill the frame, but not rat-like. The director wanted them to be cute and pretty, but at the same time, realistic. So, we had lots of trial and error, particularly during the first few months. We also did lots of work on the rig and the fat layer beneath the skin, which is like a sack. When the skin and hair moves, the fat sack moves accordingly.”

For the mouse’s hair, the studio relied on its Furtility software, proprietary hair and fur technology first developed for 10,000 BC (see “Making History,” March 2008) and The Chronicles of Narnia: Prince Caspian (See “Animal Kingdom,” May 2008). Because the studio had moved to Pixar’s RenderMan 18 with this film, the team developed a new specular model to scatter light more effectively and efficiently in white fur.

“This was the first time we have done such a large number of shots with fully ray-traced fur,” Ledda says. “But, the new shading system rendered faster and gave us more iterations than what we had in the past. We were on the cusp between RenderMan 18 and 19, but we decided to take the cautious approach and stick with 18 for this film. Our shading team will adapt the new work we did on the fur shading into 19.”

If Wishes Were Horses

Like all the eligible maidens in the kingdom, including her stepsisters, Cinderella wants to attend the king’s ball and meet the prince. So, the magical mice help her make a ball gown. But, her jealous stepsisters destroy it. No problem. Cinderella has a fairy godmother. Fairy godmother turns Cinder­ella’s rags into a gorgeous gown. She gives Cinderella glass slippers. And, she casts another spell: A pumpkin becomes a golden carriage. The mice transform into horses. And a lizard and goose become coachmen. Cinderella will arrive in style. But, the spell ends at midnight.

In the film, Cinderella’s helpful mice are always digital characters.

“Turning the mice into horses and then back into mice again was the biggest challenge in the film for us,” Ledda says. “We didn’t want the scene to look painful. We wanted the mice excited to become horses.”

The transition happens quickly. The mice become horses in approximately six shots. They switch back during the midnight rush in close to four shots. But that didn’t make it easier.

“We didn’t want to linger on the transition, but it was a challenge to turn four mice into horses in five or six shots,” Ledda says. “And, they kept changing the cuts. In the end, it didn’t take long to achieve the transition, but the process to get there was time-consuming. It took a huge amount of previs and postvis.”

Three rigs per character made the transition possible. One rig managed the characters as mice and one as horses. A third was a blend between the other two. Animators could decide which rig to use to animate any section and what to blend between.

“The third rig would understand the scale the animal was at and what part to use,” Ledda says. “The final rig created the cache. [During the transformation] a character could have mouse feet, a horse’s neck, and horse ears. When the neck got longer, the rig would drive the fur system to create a horse’s main, but the animators could still mainly have a mouse. In one shot, for example, we had a mouse running with a long mane for a few frames.”

Lizard Lips, Goose Feathers

The director wanted the other two transformations, that of the lizard and goose into coachmen, to be realistic but more cartoony than the mouse transformations.

“The lizard has big eyes and looks a little surprised when he’s zapped by the fairy godmother,” Ledda says. “The fun bit was creating the different stages. We used the same basic method as for the mice, but we had five stages and more technical animation. The cloth simulations made it more complicated. So, we had concept artists create designs for a lizard with shoes and a hat, a lizard tail that turns into a coattail, and so forth. It was quite fun. The lizard scales become cloth-like, the tail opens, and he gets a cravat, a scarf, and a hat. Animators would drive the first passes, and then technical animators added the cloth simulations for detail. The challenge was to make it look like fun and not creepy. The lizard is proud to be a human. He’s happy to help Cinderella.”

At top, the film plate before CGI. At bottom, one stage of a partially transformed computer-generated lizard composited into the plate.


The goose needed a slightly different system to solve a big problem: how to turn feathers into hands.
“We had lots of stages with a half human/half goose with feathered hands, but to have a human without hands is not appealing,” Ledda says. “So we had to be smart about what to hide and what to show. What was interesting, however, was having a goose head on a human. So, we played with that idea. As the coachman is driving and the coach is about to turn into a pumpkin, his head turns into a goose head with a big hat that covers his eyes.”

After a first pass in animation, the fur and technical animation team managed the different materials mixing into one another. During the transformation from goose to human, the feathers turn into a beard with the help of MPC’s Furtility.

Pumpkin Spice

Just before midnight, Cinderella makes a mad dash for home in her golden carriage, knowing the spell will break in minutes. During the 150-shot sequence, all the animals start turning into their original forms. Mouse whiskers and ears appear on the horses. The gold leaf on the carriage turns green, and the green leaves flutter and fly away.

“We played with the idea of the carriage going back to nature,” Ledda says. “We have shots of Cinderella panicking as vines grow inside. We tried different versions, from comical to dangerous, with the pumpkin getting smaller and smaller. But in the film, the whole carriage loses shape until there’s no carriage any more. Only a massive pumpkin with Cinderella inside.”

As they did for the animals, to transform the carriage into a pumpkin, the team worked with two main models and rigs. One was the golden carriage. The other was a big pumpkin covered with vines and leaves, and with vines in loops for the wheels.

“We had different stages between,” Ledda says, “hybrid versions with pieces of a carriage and pieces of a pumpkin. The trick with this transformation and all the transformations was extensive postvis to show Ken [Branagh] the different stages. We had a lot of back and forth, and any time the edit changed, we had to go back and revisit the transformation.”

The exterior locations in Cinderella are fully CG or a combination of plates and CG. Top, the plate. Bottom, CG structures composited into the plate.

As Cinderella bumps along inside the giant pumpkin, the pumpkin hits a log and breaks apart. For this, the artists used Kali, MPC’s proprietary rigid-body system. Inside, we see pumpkin seeds and a transformed Cinderella.

“She’s catapulted out, and there’s a nice little moment,” Ledda says. “She leans on the ground. The mice and the lizard and goose jump out. The mice are really happy. They remember they were horses and still act like horses, but it’s subtle. And then they crawl into her glass slipper and she carries them home. It was complex. There is refraction and caustics in the glass shoes, and it’s raining. It’s one of my favorite shots.”

Artists at MPC London created the assets, the rigs, and the fur. Once built, the characters and carriage moved to Montreal for animation, rendering, and compositing.

“We also had a huge number of invisible effects to create the Cinderella world,” Ledda says. “The production had set locations – her house, the interior of the palace, and so forth. But the exterior work is either fully CG or a combination of plates and CG. Our production supervisor, Charley Henley, shot helicopter plates so we had natural camera moves. But, we had to populate big sections with a slightly old-English world. And, we had big, wide shots that hadn’t been filmed. Although the close-ups in the palace are practical, when Cinderella runs away from the prince at the ball, the shots were all-digital except for the actors.”

“It was our biggest show in Montreal,” Ledda adds. “And it was a big challenge. Cinderella’s world is pretty and pristine. We couldn’t hide behind big camera shakes and smoke.”

There are no battles in Cinderella. No warriors. No explosions. No spaceships.  Only magic, courage, and a little kindness. Radical.