Flying Down to <em>Rio</em>

In a year dominated by sequels, Rio (opening today from Fox) follows Rango [1] as one of the few original bright spots. And bright is the operative word for Blue Sky's sixth feature, a musical extravaganza about the last two macaws of their species: Blu (voiced by Jesse Eisenberg), who can't fly, and Jewel (voiced by Anne Hathaway), who refuses to open her heart.

Directed by Rio native Carlos Saldanha [2], Rio captures the landmarks and rhythm of the beat that define this famous Latin American paradise.

However, Blue Sky certainly had to raise its game to achieve the level of animation necessary to match Saldanha's ambitious vision.

Birds were the first challenge, of course. There are 12 bird species (chicken, crow, egret, frigate, goose, macaw, sparrow, spoonbill, toucan, cockatoo, cardinal and canary) and a total of 51 unique ones. The hero birds required special rigging for the wings, which double for gesturing when not used for flying. In the case of Blu, that's most of the movie. In fact, Blu's entire groom had around 5,000,000 individual hairs to make up all of the feathers.

"The wing rigs are complicated and you want to give them some personality and the ability to emote and articulate their feathers," suggests Robert Cavaleri, CG supervisor. "And those are two very different kinds of control sets that you have to blend together in a way that allows to them to go from being like a normal bird and something that can be caricatured in a particular way."

According to Galen Chu, supervising animator, "Rigging helped us use these wings like fingers to be able to point and grab an object. It took about nine months of back and forth between modeling, rigging and animation to make it work."

Fur and feathers are done procedurally at Blue Sky: the grooming tools are created in Maya [3], which is the primary software, and then translated into the proprietary renderer, CGI Studio, which contains a special ray tracing technique.

"The feathers tend to overlap and penetrate a lot, so as you're evaluating the character animation, there's a lot more attention to detail and it can be somewhat difficult to control," Cavaleri adds. "We have a lot of tools now to manipulate the feathers, but considering that there are so many of them, it tends to go slower and the birds tend to be heavier than the humans."

Speaking of which, Rio represents the first Blue Sky film populated by humans (Ice Age [4] contained glimpses of cavemen that don't speak). While they're definitely stylized, they certainly had to have pleasing skin, so Blue Sky utilized sub-surface scattering as part of a larger global illumination effort that goes beyond the Connecticut-based studio's signature ray tracing rendering with its proprietary CGI Studio.

Linda (voiced by Lesley Mann), for instance, who reared Blu in Minnesota, required the most attention, including her long, flowing, brown hair. "We had to improve the hair rig called Follow Through for Linda," explains Matt Simmons, animation technical lead. "The R&D guys rigged up the fur that we have so we were able to do more poses for Linda's hair and handle the collisions. If a hair went right through her face, we needed a nice way of getting it out of there so it looked natural."

Chu says her mouth was also tricky, "and the animators tended to push it a little too much on the lip sync or the expressions and it was always the job of the director or mine to pull back to where we needed Linda to be."

 

Cloth, too, was such a vital component that, for Rio, Blue Sky created a department strictly devoted to cloth and sim with a dozen artists so they could handle the demands of the Carnival parade. There are 50,000 people for one pull out shot and it takes 3,000 fans to fill one set of bleachers. In addition, the fans consisted of 10 unique people, each able to do two different types of motion: "cheer" and "cheer crazy." Blue Sky was able to swap outfits on the people in the stands to help with variation (each one had about three or four different outfits). However, each section of the parade only had one costume type. Even the characters in the parade that are super close to camera were part of the crowd cycles.

"For crowds we created proprietary techniques that allowed us to pre-store information earlier so you didn't have to load it all into memory at the time of render," explains Cavaleri. "That was important because we had to find a way to produce all these crowd shots and, in some instances, we could layer the crowds together, but [not always]. So we came up with a way to calculate and pre-store a lot of information earlier and write it on a file system that allowed us to iterate quicker on the crowds and allow that complexity to be rendered. There's a shot in the parade reveal that to render a single frame of that crowd layer, which is basically the people in the stands, took about 65 hours and 6.6 gigs of RAM. And there were 2.2 billion rays that were fired in that particular layer.

"We found clever ways of getting more with less. Blue Sky generally does not use texture maps, so Linda's material was defined procedurally. She was produced with 10,764 lines of studio ++ script. And one dance costume has 24,000 procedurally created, hand-adjusted sequins."

But Simmons says "they're maxing out the current technology because that pull-out shot had 30 plus animation files, which is right back to where we were on Robots [5]. So we're constantly trying and improve and look for new ways of handling these humongous scenes in future movies."

Blue Sky was also able to come up with some very unique tools using cloth technology for the chain that linked Blu and Jewel throughout the film. The tool was so robust that they were able to hand it to the animators and let them manage the interaction between Blu and Jewel. They were even able to direct the simulation, and only set keyframes when required to pass through a shape. "We knew we nailed it when the animators did a test and had Blu and Jewel jump through the air and the chain formed a heart and relaxed into a normal shape again," Cavaleri says. "And it looked completely natural and seamless."

Rio itself is like another character, which provided its own set of challenges. Blue Sky took some liberties, not surprisingly, and pulled in some of the beach shorelines and other key landmarks to stylize it just a bit. "And once we had the key landmarks identified, we constructed the buildings and actual town locations, the favelas and so forth," Cavaleri reveals. "And a lot of those buildings were set dressed procedurally with a tool that we created to fill in and block out city streets and put the road in between. But it was advantage using a known location. We also projected the imagery in Nuke onto geometry and that allowed us not to have to render the background in every single shot. You could even drift the camera on it."

Then there was the foliage, which had to be very detailed, especially the deciduous, small leaf trees. How to move the leaves on the trees to give the environments more life? This was a breakthrough. "Another was how to populate the hillsides in the vista views to construct that lush landscape," Cavaleri adds. "We ended up creating a new technology -- an advanced form of displacement -- that allowed us to achieve the lush looks. If you think about how a painter might just press the brush onto the canvas to create a splotch of paint that actually looks like a crop of trees. In a way, we were able to achieve the same result using this technique without having to instance and propagate hundreds of thousands of trees across the hillside."

Bill Desowitz is senior editor of AWN & VFXWorld.