'Beverly Hills Chihuahua': Tippett's Chattering Class of Pooches

In the 13 years since the talking animals of Babe earned a visual effects Oscar for Rhythm & Hues, we've seen increasingly articulate menageries on screen. Walt Disney's Beverly Hills Chihuahua (opening today) features a chattering class comprised of all manner of pooches, voiced by an enviable cast that includes Drew Barrymore, Andy Garcia, George Lopez, Edward James Olmos, Cheech Marin and Paul Rodriguez. Director Raja Gosnell also brought his experience integrating digital character animation into live action films, having directed two movies starring Scooby Doo.

But Beverly Hills Chihuahua required more than the muzzle replacements of real dogs and a bevy of their digital doubles. It also called for all-CG animals that could deliver lines and look real enough to be believable alongside photographed dogs. "This movie is very much in the vein of Shaggy Dog," says James W. Brown, animation supervisor at Tippett Studio. The Northern California shop has become known for its animation of CG critters, especially recent characters like Templeton the Rat in Charlotte's Web and the chipmunk Pip in Enchanted. Beverly Hills Chihuahua featured two CG critters that had to have acting chops: The hyper Manuel the Rat (voiced by Marin) and the laid back Iguana Chico (Rodriguez). "Yes, another rat," laughs Brown. "We've got rats down pretty good. But this is a family film, so we didn't go for complete realism. We didn't want anybody to be grossed out by a rat."

"At Tippett, it is imperative that we view our creatures in an environment free of surprises," says Page Frakes, Color Pipeline supervisor. "On Beverly Hills Chihuahua, our art, TD and compositing groups utilized Cine-tal's Cinespace for film-look emulation and we were happy with the results."

The Dog's Life

Brown explains, "In the 165 shots we did for the movie, there were a lot of crowd shots of dogs and digital doubles. We did a number of digital doubles of stunt dogs, especially for things that the dogs couldn't physically do, like jump onto a moving train." Tippett Studio employed data captured by Realscan 3D to create digital versions of actual dogs in the film. Realscan was able to deliver accurate likenesses of these dogs by using a handheld system that merged data from several capture sessions. The resulting full body scans were delivered to Tippett, while scans of the dogs' heads and muzzles went to Cinesite for the muzzle replacement animation.

But it is in the scene where pampered pooch Chloe (voiced by Drew Barrymore) meets the rat and his iguana pal that we see the different types of animation in Beverly Hills Chihuahua come together. "Chico and Manuel are best friends who try to con Chloe out of her very expensive, Harry Winston diamond collar," says Brown. The attention-getting aspect of the con is that the duo makes it appear as if the iguana is eating the rat. So the physical interaction among the characters was key.

"Manuel pushes on Chloe and rubs her fur," explains Brown. "So on set, the production people prompted the dog playing Chloe to react. Then, when we put in Manuel, we did some fur displacement on the body of the real dog where he touches her. It's in there because at Tippett we love to go for realism!"

Paling Around

Brown observes that the biggest challenge wasn't with the dogs but with the close interaction between the film's CG animals, Chico and Manuel. "The big issue that we had with this, which is something we hadn't dealt with a whole lot before, is that those characters are so close in their friendship as con men that the personal space around them is very small. They're bumping into each other and trying to hide behind one another, so there's a real interaction. We had 65 shots of Manuel and 53 of Chico and nearly every sequence had them together. They push each other so much it was almost like animating one character."

Brown led a team of 16 animators on Beverly Hills Chihuahua, including lead animators Ryan Hood and Mike Brunet. Lead character rigger Jeremie Talbot also played a key role in selling the interaction between Manuel and Chico, notes Brown. "When the rat pushes on the iguana's ribs, for example, we see his elbow going into the skin a bit. We used our deformer system to add these types of things. A lot of it is based through (Autodesk) Maya but we do have some proprietary plug-ins that our rigging department wrote through MEL scripts. They allow our animators to create these deformers a lot faster than if we had to do it ourselves."

Imitating Life

Unlike Templeton the Rat for Charlotte's Web, this time Tippett chose some "off campus research" to get the correct look for Manuel. "He's a wood rat, about 6 to 8 inches long, which is larger than your normal rat," says Brown. "So we went to the Lindsay Wildlife Museum near Berkeley to watch a rat there that had been rescued. We got to sit and watch him and what we noticed was his high energy. Nothing was slow. We couldn't capture that completely for our rat because we wanted audiences to be able to read his behavior on screen.

"The iguana was an interesting challenge because doing a reptile was fairly new for us, and this one had to act believably," Brown recalls. "A guy who works here is big into reptiles and he knew a guy who brought in a couple of iguanas. One of them was five feet long. We had four video cameras going at once while the iguanas were running and climbing up and down on things. We ran four cameras because iguanas are very skittish animals and they can move with great speed. Luckily, there were two of them so we got a ton of reference footage from every angle.

"The owner had them slightly trained -- as much as you can train an iguana," laughs Brown. "They'd come for food, but the main thing we realized is that they're very lazy animals. They only move when they have to. They'd stop mid-stride and not settle their feet. We saw those kinds of mannerisms as the tidbits that we wanted to use with our character. That really helped with his personality, since he was the lazier of our two characters." The characteristic way that the reptile's skin bunched up around its joints was also essential to include. "Our rigging department set up a lot of deformers that are automatic, based on the rotation of the joints. So when we would rotate the shoulder area, the skin would bunch up." Brown's team realized that they'd have to play with the size of the iguana from shot to shot so that it would fit believably in scenes shared with the small chihuahua and even smaller rat.

Selling the Surfaces

The very different surface textures of the rat and iguana would also be key to a successful look. To get the scaly sheen of iguana skin, Tippett's paint crew worked from extensive photographs. "They painted the colors and the bump maps," says Brown. "And we did some displacement on top of that. Our art supervisor came to our reference shoot to touch the iguanas and feel their skin, which has a bit of a sheen on its scales." Brown's team investigated the idea of actually animating separate scales, rather than suggesting the iguana's skin surfaces with textures and bump maps. "We actually tested scales at one point to see what it would get us. But the amount of time it would take to render just didn't benefit us."

In creating the furry rat, the Tippett animators are proven pros. The studio's proprietary fur tool, Furrocious, has been refined since Charlotte's Web, enabling the animators to create fur that moves dynamically with the character. Brown explains, "As animators, we hadn't able to render our own furred characters, so we just worked with characters without fur. We'd run them and not really know how the fur would work. We've gotten to the point now where we can actually run our own fur dailies and see how a character is going to look furred, which can change the silhouette a bit in some poses. It is extremely helpful to know where you need to push your silhouette, or make a facial expression read better because fur does dampen down some of that. Of course our animators still work closely with our lighters and compers and go back, if necessary, to get the performance. For example, we'll ask them to put a little more light into an area to sell a silhouette if we feel like we're losing it."

Tippett Studio has refined the Furrocious tool to be increasingly more interactive, and though that slows down the animators' machines, Brown says they now have some ability to experiment interactively with a character's fur. "We can work on a character rubbing his chest or stroking his fur and then have that go to our effects department. They can use that collision of the character's hand stroking its fur as a way to manipulate the fur so it looks like the character is actually pushing the fur around."

The Movements That Matter

Tippett Studio had to strike a delicate balance as they animated realistic-looking animals doing unrealistic things like speaking and walking on their hind legs. As Brown notes, "Once we started animating the iguana we realized we didn't want to do a whole lot with this character. We got to the point where the director said the iguana was too realistic and a little scary. So we backed off and made him a little more appealing. Also the size of the iguana didn't give us room to stand him up on his hind legs and gesture a lot with his hands, and so much of his weight is on his four limbs. With the rat we could sit him up and he could gesture with his hands and then walk for a step of two on his hind legs. As soon as we sat the iguana up on his hind legs it looked wrong, no matter what we did. He lent himself to more realism.

"For the animation of the rat, we had guidelines for things we weren't allowed to do, like spread his fingers out because it would make him look too human. Because it's a family film, we pulled back a bit from some of the 'rat qualities.' He gestures with his hands more and pulls his elbows out a little from his body."

Adjusting the rat's snout to speak was something that Tippett Studio had experience with from Charlotte's Web, but Brown admits that getting the iguana to speak was tricky. "If you look at how a person talks, the corners of the mouth move from front to back and up and down. As soon as we did that with the iguana, his face looked like rubber. He looked fake. The scales on his face allowed for some movement, and we handled a lot of dialogue by closing his jaws with minimal lip movements. He was more Muppet-like. We used the expressions in his eyes to really sell him, and we took the liberty of giving him eyebrows. We didn't give our iguana double-eyelids, by the way, because it started looking creepy. But the main way to get an 'emoting iguana' is by doing a lot with his body posture."

Sims for Effects

When we first meet these characters, notes Brown, "Manuel is in Chico's mouth. That's the con that they're pulling on Chloe in order to steal her diamond collar. Manuel climbs into Chico's mouth to make it look like the iguana is eating him." (As an aside, Brown chuckles, "Of course people don't realize that iguanas are actually vegetarians!") The production originally wanted Manuel to get spit out of Chico's mouth and be sopping wet." The studio's ability to simulate wet fur was a highlight of the sequence in Charlotte's Web when Templeton the rat takes a milk bath, and Brown's team was able to simulate something equally realistic for this sequence in Beverly Hills Chihuahua. "But our wet fur looked so real it actually looked kind of gross," Brown recalls. "The director saw Manuel lying in a pool of saliva and said, 'Whoaaah. That's a little scary.' We didn't want people focusing on the wetness as much as the 'con' itself. So we backed off and took out about 95 percent of the wet fur. He now just looks a little damp!"

A more difficult sim was placing the diamond collar on the rat and having it move believably against the animal's fur. As Brown explains, "Once they steal the collar, Manuel wears it like a bandoleer. Animating what was basically a rope faceted with diamonds meant it could only move certain ways. It was a huge technical challenge to get that collar to wrap around him and have him be able to emote, and not have tremendous troubles with intersections with his fur. Again, that 's when our improved fur tool came in handy. We could have the necklace interacting with the fur, so there wasn't a huge intersection of fur piercing diamonds. The fur actually moved around the diamonds. The fur interaction with the necklace was a sim, but the actual the necklace itself was 90% hand animated. That was the big issue for Manuel.

"The big issue for Chico was his dewlap -- that flap of skin that hangs from an iguana's jaw," explains Brown. "It's like a giant piece of cloth. They use it to show emotion. They bob their heads and throw their dewlap out to look bigger when they're frightened. When we had the real iguanas here, their trainer put a mirror in front of them, which made them think that there was another iguana and they started puffing up." Brown's team used that footage as a guide to animating this behavior. Fortunately, he recalls, "Ninety percent of this we could do as a sim."

This kind of attention to detail is one of the reasons that Tippett Studio has become increasingly well-known for animating realistic CG animals. When he thinks about the fact that he gets paid to watch iguanas and rats run around, however, he has to laugh. "Yeah, it's fantastic, isn't it?"

Ellen Wolff is a southern California-based writer whose articles have appeared in other publications, including Daily Variety, Millimeter, Animation Magazine, Video Systems and the website CreativePlanet.com. Her areas of special interest are computer animation and digital visual effects.