Alien Re-Creation
Issue: Volume 38 Issue 2: (Mar/Apr 2015)

Alien Re-Creation

DreamWorks animation populates a CG feature with cute six-legged aliens, weapons made from bubbles, and a precocious tween.

Finally. We’ve enjoyed years of apocalyptic alien attacks and frightening invasions in feature films. We’ve recoiled from horrific, villainous creatures from outer space in Steven Spielberg’s War of the Worlds, Ridley Scott’s Alien, Guillermo del Toro’s Pacific Rim, and so many other dark action-adventures. Now, at last, friendly aliens have landed in a feature film.

DreamWorks Animation’s Home sends a spaceship filled with cute little Boov trying to escape a mortal enemy from one planet to another. The six-legged, barrel-shaped aliens need a new home, a place to hide. The planet they pick is ours.

Based on the Adam Rex children’s book “The True Meaning of Smekday,” Home stars Steve Martin as Captain Smek, the leader of the Boov. Rihanna is Tip, a resourceful, almost-teenage girl and the only human to avoid capture. Jennifer Lopez is Tip’s mother, Lucy. Lucy doesn’t have Tip’s luck. The aliens capture her, along with the rest of the human race, and take them who knows where. Jim Parsons is Oh, a banished Boov who accidentally tells the enemy where the Boov landed.

The bubbles have iridescence only around the edges, to better see the Boov inside.

The story centers on Tip and the outcast Oh. “Even though we made substantial changes to Adam Rex’s plot, the characters are his,” says Director Tim Johnson, who also directed PDI/DreamWorks’ Antz and Over the Hedge, and was executive producer on How to Train Your Dragon. “It’s a story about love and sacrifice that takes the characters from extremes to uniting.”

Oh is arrogant about humans. Tip hates him. She can’t trust an alien who took away her mother. The two have a wary relationship until they break down the barriers. Oh turns a car into a flying hovercraft and helps Tip search the world for her mother. The car flies the two characters around a world transformed by the well intentioned but clueless Boov into a bizarre landscape.

“I moved my first mouse in 1985,” Johnson says. “Now, I can pretty much let my imagination go wild. Some things are challenging, but we have the tools and talent to pull them off.”
So, how did he have the aliens capture the humans?

“The aliens flick a switch that turns off gravity and scoop up all the humans,” Johnson says. “We open the film from the aliens’ point of view and have the invasion take place on a happy day. The aliens fill the sky with bubbles. It feels like a festival. They believe they’ve arrived on a planet occupied by naïve primitives who will benefit from their arrival. The aliens give the humans ice cream and deposit them in a happy human town. They have no idea how devastating they’ll be to our culture.”

Beware friendly aliens armed with bubbles.

Bubble Trouble

Why bubbles?

“I’m a huge science-fiction fan, but I feel that the genre has fallen into stereotypes,” Johnson says. “The spaceships in Star Trek look like the spaceships in Battlestar Galactica and the spaceships in Star Wars. They all have blasters, lasers, and vehicles with rocket boosters. So, I wanted to give the Boov an unexpected look and feel. The source of their technology is gravity, and bubbles are the primary component of that. Even their weapons are bubbles.”

DreamWorks brought bubble experts into the studio to learn how bubbles oscillate, wobble, rotate, and move. And the crew played with sizes and scale.

“The bubbles in the film are generally like bubbles you would imagine, with subtle differences,” says Mahesh Ramasubramanian, VFX super­visor.  “Usually, people play with refraction, which makes bubbles look thick. We stayed true to physics. The bubbles are thin and don’t refract. But, they have a lot of iridescence, oily patterns like those you would expect in nature. That makes them look like bubbles and not balloons or glass spheres. But, we limited the oily texture to the edges because when Boov are inside, we didn’t want to cover their faces.”

A bubble’s color depends on its use. Communication bubbles, for example, are turquoise.

“One character sends news about a fugitive, using a small, turquoise bubble with an LCD film inside showing the picture of the person being chased,” Ramasubramanian says.

Red bubbles are aggressive.

“The Boov unleash these innocent-looking red bubbles,” Ramasubramanian says. “As the bubbles get close to a building, they pop and create a hole. Then the Boov use a bubble with another color that is kind of like a tube, to suck people out from inside and transport them away.”

Where did they take the humans?

“The Boov built seven billion homes with white picket fences in Australia,” Johnson says. “The ceilings are a little low, though, because the humans looked shorter from space.”


The low-ceilinged houses landscaped with picket fences look normal compared to the rest of the world once the Boov begin rearranging it.

“Tim [Johnson] always reminded me that the aliens didn’t mean any harm,” Ramasubramanian says. “They came as interior decorators. They thought the humans needed help, so they helped them. They saw that the humans liked things manicured, so they built a whole country, complete with small bushes, garden gnomes, and roller coasters. They said, ‘Let’s have the humans stay there while we’re in other parts.’ The Boov transform the world, but they always think they’re helping.”

The transformations these interior decorators produced looked more like something René Magritte might paint than a page from “Architectural Digest.” Postapocalyptic was never so weirdly charming. For example, the six-legged Boov decided that bicycles weren’t useful. So, as part of their tidying up, they decided to collect the bikes with a bubble and store them. In the air.

“We limited ourselves to the few technologies we assume the aliens have,” Ramasubramanian says. Bubbles and gravity. They had small spheres that would locally control gravity, so they scanned the bicycles with a gravity ball. The bicycles stuck to the ball, which floats.”

Not only bicycles. In every scene that has characters flying in the car or sitting on a hilltop, you can see floating balls in the background.

“It looks surreal,” Ramasubramanian says. “Playful. One is full of pianos and you hear tunes as they fly by. One has picnic tables, so the characters sit on a bench, have lunch, and then get back in the car and fly on.”

As Oh and Tip fly around the transformed world looking for Tip’s mother, they might see a Roman coliseum floating over a US landscape, the Statue of Liberty surrounded by Roman monuments. In one scene, a Ferris wheel floats in the sky. In another, an Egyptian pharaoh.

“The Boov could pick up any object and float it over the world,” Ramasubramanian says. “It didn’t matter. They were just doing interior decorating and keeping everything floating. Playful things. Sometimes modified. The captain of the Boov liked to put his image on everything.

There is one sequence, though, in which the world doesn’t look like Dali stopped by.

“Oh and Tip are sitting on the hood of the car, which is floating above a quiet ocean under the night sky,” Ramasubramanian says. “The sky is clear; it only has stars. Oh realizes he has not completely understood humans. That what the Boov have done has been horrific for the humans. Tim [Johnson] said to let that sequence be only about the characters. It’s the one sequence in which you wouldn’t notice anything has changed. Except there is an alien on a floating car.”

Boov Designs

You could sum up the character design for the Boov with one word: adorable. Or, maybe two: adorable and unique. The short little Boov have six legs, “nostricals” that curl like tentacles on the side of their heads where ears would be, and two arms. Their legs have no knees, but their arms have elbows that can bend to a sharp point when they’re angry. And, they can uncurl their nostricals like an elephant uncurls its trunk. But in general, they are soft and squishy.

“I’m a Comic-Con habitué,” Johnson says. “It’s a joyful, fun event, but it’s really hard to have a unique voice. A lot of character design feels repetitive. It’s UPA flat [like Mr. Magoo or Gerald McBoing Boing], Japanese anime with adorable large eyes, or superhero athletic. Everything seemed to fall in those categories except the collectible vinyl toys from artists all over the world. The desktop toys were unique in their design. So, I bought a bunch. I told Takao Noguchi, our character designer for Home, I wanted to have the Boov look like a vinyl toy you could put on your desk to hold a pencil.”

Oh’s normally purple color changes to reflect his emotions.
The Boov’s most endearing feature is that their naturally purple color changes to reflect their emotional state. They literally wear their emotions on their skin. They glow. They have stripes and patterns.

“Some emotions, like fear, instantly change their color,” Ramasubramanian says. “Others have more subtlety. When a character lies, we wanted to feel like the color waits until he feels bad about it. The color-­changing was complicated to produce, but it gives a nice dimension to these characters and to important story points.”

Ramasubramanian notes that Noguchi referenced aquatic animals for the Boov, using a six-legged squid for the body and legs, and a cuttlefish for the changing color and patterns.

“The cuttlefish change patterns really fast,” Ramasubramanian says. “It’s amazing. It feels like the changes come from within. So we developed a new shader we called Parallax to make texture on a Boov look like it’s inside. The shader parallaxes between the surface and the inside so that it looks like the change is within.”

The shader worked well, but the look wasn’t what they wanted.

“It looked creepy,” Ramasubramanian says. “It looked like veins and arteries, which is what we set out to do, but it looked more organic than we wanted. It was more fun to have [the patterns] skin depth. So, we simplified the patterns. We used the Parallax shaders in other places, though, when we wanted the texture to feel deep.”

Animators manipulated the Boov’s six legs two at a time and uncurled the foreground Boov’s nostricals into horn-like shapes.

The design language for the film gave the Boov circles, the humans rectangles, and the enemy Gorg triangles. So, rather than veins and arteries for the Boov, the artists designed simple arcs and

“The color changes kept [the arcs and squiggles] saturated and moving along the skin from the head, the heart, or from an impact point,” Ramasubramanian says. “The design was simple, saturated, and playful.

“I’m really happy about the work we did on the characters in visual effects,” Ramasubramanian adds. “This is an intimate story that stays close to our two characters. We wanted them to look rich and appealing, and I think the color changes for the Boov and Tip’s costumes and hairstyles helped.”

Tip Top

The film Monsters, Inc., from Disney/Pixar, broke computer graphics ground in 2001 when the little girl Boo touched the hairy, blue monster Sully. Pixar scientists had invented a new state-of-the art hair and cloth simulation engine to solve the interpenetrations caused by that simple action.

Today, animation crews take interactions like that for granted. But even so, in most animated films, the star has one hairstyle and, maybe, a couple costume changes. In DreamWorks’ Home, 12-year-old

Tip has seven costumes and six hairstyles.

“In live action, costumes are so important they give costume designers an Academy Award,” Johnson says. “But in CG, we typically see one T-shirt and one hairstyle. We designed hairstyles and costumes for Tip in every scene. We treated her like a 12-year-old girl. As she goes from northern snowy weather to summer, she removes layers of clothing. It serves as a metaphor to warming up to the alien.”

To manage Tip’s hairstyles, the team relied on new technology called Willow. “The biggest change was that rather than having hair go through many departments – surfacing, effects, modeling, and animation – we tried to have character effects own the process,” Ramasubramanian says. “With Willow, they can iterate faster. They can make hair move and react the way they want, and get quicker feedback through rendering.”

Most remarkably, animators could have Tip touch her hair. Repeatedly. She ties her hair back into a ponytail, tugs it loose, and pulls a hoodie overtop. In some scenes, Tip changes her hairstyle within a shot.

“Even in our studio, we have a joke where we say no one wants physical contact,” Ramasubramanian says. “We count and limit the number of times. But, the ability to make physical contact helps with the storytelling. We noticed people with curly hair tend to fiddle with the strands of hair, and thought that was a nice characteristic to bring out. In one scene, Tip is looking for her mom. She collects her hair, pulls it back, and puts a rubber band on it. We have a few other instances like that. They don’t scream at you. They’re something you would expect a young girl to do.”

Animating the Boov

Jason Reisig, the head of character animation at DreamWorks for Home, worked with a surprisingly small crew of animators to perform Tip, Oh, and the other characters in the film.

“For a majority of the time, we had less than 20 animators, although during the last three weeks, it went up to 35,” Reisig says. “We had a longer schedule than usual, so that allowed us to stay lean longer. There was a little ebb and flow, but even at its biggest, it was a small crew and a tight group.”
Because the film was primarily about Tip and Oh, everyone animated both the leading characters.

“We had four supervisors, with a fifth that came on at the end, and their teams were never bigger than six or seven,” Reisig says. “The smaller group could focus on the characters and nail down the style of the film. The big challenge early on was the odd-looking Boov. How they moved. How alien they were. They have this elephant trunk nose where their ears are. Their color shifts. They have six legs. There were a lot of unknowns. So we did a lot of exploration into what they would do.”

Because the Boov have
six legs, the typical bipedal rig used for many characters wouldn’t work.

“Tim had specific ideas about how he wanted the legs to feel and the controls we’d create,” Ramasubramanian says. “So, we kept the rig clean; it’s designed to produce clean lines. The Boov don’t have knees or feet. They have simple, small parts coming out from their belly. But, their legs don’t go all the way into the body. When the characters stand, there’s a little pressure on the bottom of that part of their leg, which creates a bit of a bulge. That’s procedurally built in. When they straighten, the leg goes back to a cylinder. And, when they put a finger on the table, there’s a slight bulge on the fingertip.”

"I felt I was directing a performance, not the technical craft of animation"

Otherwise, the animators do the work, not the rig.

“We created cycles, but for the most part when we wanted them to step and contact the ground with weight, we just had to do it,” Reisig says. “We would do the front two like a normal fast walk, the ones behind and opposite at the same pace, and the ones on the sides more chaotic. That created a little bit of chaos, but organized chaos. A lot of times we’d plan shots by sliding the characters around and then planting the feet.”

The Boov can as easily walk sideways or backward as forward with their six legs. As they walk, they make a little bop, bop, bop noise when their balloon-like legs touch ground.

“It was tricky,” Reisig says. “Usually a legged character lifts a foot to walk and creates a nice crease where the knee bends. When the Boov lift a foot up, they squish up, like going from a long balloon to a round balloon. We used a single-axis squash-and-stretch control, and when we wanted more swing to the legs, we used FK on top of the IK. We wanted them to feel bouncy, like they were pushing their body into their feet and their shoulders into their body.”

A library of shapes for the nostrical helped the animators stay on model.

“We curled it up carefully into a shape once, and then put it into the library,” Reisig says. “It’s kind of a tube, but it’s also like a tail. We could bend it at any angle.”


Tip brought the animators back to normal – she’s a typical human biped. The challenge for the animators who performed her was in finding the personality of a not-quite teenager.

“Trying to animate a 12-year-old was surprisingly challenging,” Reisig says. “A lot of times we have cute little bouncy kids out of control or grown women to animate. Rarely do we have someone right in the middle. It’s tricky finding the balance of not quite an adult and not a teenage girl. She’s in a tough situation. She’s separated from her mom, so that’s a hard thing. But, she’s also playful. She has to decide when it’s OK to be fun, goofy, and awkward, and when she needs to be serious and take control.”

The character effects team managed Tip’s hair and cloth simulations, but with DreamWorks’ new Primo animation system, the animators could see the silhouettes.

“We could see what her shorts did when she bent, and we knew where her hoodie was,” Reisig says. “She puts her hands in her pockets and puts her hoodie on. Because we could see her with her actual hair and clothing, we knew when her hoodie hid her neck or face. It was all there in a simplified form. Having two characters in full high res has changed so much of how we work.”

Oh and tip’s slush machine-powered hover car travels past bubbles used to collect and float unwanted earthly objects.

Prior to this, the animators had to manage and limit a character’s complexity when the computer couldn’t keep up. Johnson, who directed Antz, DreamWorks’ first animated feature film, finds the progress exhilarating.

“We were the first to use Primo from start to finish,” Johnson says. “And it was a profound experience. It made me want to animate again. We used to work with stick figures, then volumes, then color. Now an animator can hit Play and watch a fully rendered version of the character. Seeing details like hair and skin color is part of the work process.

Johnson continues: “It’s so intuitive. The animators could proceed so quickly from launching a scene to roughing and blocking, I felt I was directing a performance, not the technical craft of animation. With these new tools and the talent of the animation crew, I could direct on an emotional basis: how a character’s thoughts might flicker across the face, how to change a walk based on anger or happiness.”

Freedom from Restrictions

Although it’s obvious the world transformed by the Boov is a caricatured version of the real world, Johnson made it clear photorealism wasn’t the goal.

“I think CG has gotten stuck in a photoreal rut,” Johnson says. “We have tools in computer animation and an aesthetic that’s driven by imitating the real world. We want things to be recognizable as a chair. Or, a teapot. But, live-action crews bathe a set with red light to achieve a monochrome look. They underlight. They use lighting in a theatrical sense.”

Thus, Johnson gave lighting artists working on Home permission to be theatrical. When a character is friendly, it is bathed with a soft rim light. When a character is antagonistic, a harsh underlight creates sharp edges and shadows.  

“I put a slogan up that said, ‘Continuity is for the weak’,” Johnson says. “Otherwise, it’s easy to get stuck in that loop and stop serving the emotional sense of a scene. There’s safety in being realistic rather than interpretive. If you’re lighting for the narrative, there is a sea of choices. But artists love that challenge. Our artists could use a rim light when they wanted.”

And with Primo, animators could make decisions based on that lighting.

“In a traditional animation pipeline, you have layout, camera, and animation, then you do the lighting,” Johnson says. “That’s beyond absurd. In live action or on stage, the first thing you do after blocking is remove the actors and
light. Then, the actors make decisions based on the emotional quality of the light.

With our new tools, animators could block quickly and lighting could play quickly. Encouraging that collaboration was a pleasure.”

As for layout, even though DreamWorks has a motion-­capture studio that directors can use to film animated scenes by physically moving a virtual camera, Johnson preferred to unleash Home’s virtual camera from reality.

“I’m pretty old school,” Johnson says. “When I made Antz, I felt liberated by having a computer camera that wasn’t restricted by how sore my knees were or how tall a ladder would go. I don’t want to be tied to strong physical constraints. I loved having a virtual camera not tied to reality.”

Although, given a quick glance, Home might not seem like a wide departure from other animated features. But the colorful, friendly alien invasion, the bubbles, the antigravity interior decoration, the character design, the freedom to have a little girl act like one, the lighting, and the camera work make this film unique.