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ComputerCafe Tackles 3D Challenges for Spy Kids 2
Swashbuckling skeletons, a miniature zoo, and menacing mutant animals are among the new adventures awaiting siblings Carmen and Juni Cortez, who are back in action in Spy Kids 2: The Island of Lost Dreams, which was released in theaters nationwide on August 7, 2002. ComputerCafe created extensive photoreal 3D sequences for the sequel to director Robert Rodriguez's phenomenally successful Spy Kids, which has grossed more than $100 million domestically.
"We like to stretch beyond what we've done before," says ComputerCafe digital effects producer Vicki Galloway Weimer. "The most important thing a project offers is to push the studio and advance our creativity and knowledge. It's been a rewarding experience working with Robert (Rodriguez) on Spy Kids 2. He's a creative, innovative director and was very involved in every aspect of our work."
Over a three-month period ComputerCafe's Santa Maria studio devised approximately 16 photoreal CG animals for 35 shots of two to ten seconds duration. Many feature multiple creatures, with some scenes including as many as 50 animals.
"We tried to keep the animals as anatomically and physically correct as we could, right down to the fur, texturing, color and movement, so they look real and seamless," reports ComputerCafe animation supervisor Domenic DiGiorgio. "We spent a good bit of time studying African wildlife documentaries and referencing real animals to match key moves with the right walks and gaits for more believable personalities."
ComputerCafe was challenged to blend the bizarre mutant animal combinations, which were more than just join two halves of very different creatures. For example, the catfish has fur and scales, the head of a fish and the body of a normal cat with tail fins.
ComputerCafe animators modeled all the animals with Lightwave 3D using subdivision surfaces. With this technique, the animators could work with low-resolution models, then render at any resolution desired. "That let us animate very quickly because there's less data to manipulate. We can increase the surface subdivisions when ready to render the final imagery," DiGiorgio explains. "We could preview chunky, boxy animals on screen but render them smooth and clean." The technique was also helpful in controlling scene complexity by decreasing resolution for animals blurred by depth of field.
Character animation was done with Project: Messiah, a Lightwave module, which offers additional animator controls not found in the basic Lightwave package, which was employed for lighting, texturing and rendering. "Because 90 percent of the animals had fur, and fur is traditionally tricky, we used Worley Labs' Sasquatch, a Lightwave plug in and fur shader, which we pushed to the extent of its abilities," DiGiorgio adds.
"Making fur look realistic, and creating correct and realistic movement, were key issues," he continues. "A lot depended on how we rigged the creatures to show their muscles moving, their lopes and gaits. Because most had four legs, each animal was twice as complex, and required a lot more animation per animal than do two-legged creatures."
The mutant sheepdog proved particularly challenging. "It's a sheep with a bulldog's head and feet," DiGiorgio says. "We didn't want it to look like a dog wearing a sheep's coat. Wool proved to be much more complex than fur to render. It gave us some hairy moments!"
"The most challenging aspect of creating The Spork was developing a flying style to match its bulk," admits DiGiorgio. "The Spork is a fat, heavy creature which almost struggles to stay in the air. It moves its wings with big, labored flaps as if it takes enormous effort to lift its' weight." To give greater realism to the wings, the animators modeled and added translucency to each feather individually.
Although ComputerCafe lit the creatures to match the live-action plates they would be composited in, director Rodriguez often asked animators to enhance a shot, by making the creatures' lighting more menacing or mysterious, DiGiorgio notes. Sometimes the lighting was altered so the animals would stand out better against the background plate.
Under digital effects supervisor David Ebner, the Santa Maria studio composited the zoo and mutant animals' sequences using eyeon's Digital Fusion as their primary compositing package and 5D's Cyborg for keying greenscreen elements, which, like the movie itself, was shot in 24p HD.
"There is compression in the HD image so when you pull mattes the blue video channel is very noisy, making it difficult to get a good key," Ebner explains. "Out of all the compositing packages we have, Cyborg has the best keyer and allowed our animators to build frames together and play them at high resolution and full 2K resolution, revealing more detail before we finished out," Ebner says. ComputerCafe wrote a custom HD grain tool to add the format's subtle grain back into composited shots.
DiGiorgio and Ebner found a number of advantages in working with HD source material. "Everything was digital and at the right frame rate so we were able to work immediately without waiting for film scans," DiGiorgio says. "I was very impressed with the quality of 24p HD. It was very close to film."
"We received an animatic that was originally done in Alias|Wavefront Maya, by animator Chris Olivia," says Jonathan Stone, associate producer at ComputerCafe, Santa Monica. "The scene data came on CD and was integrated it into our studio's Maya to Lightwave pipeline. The animatic was low-resolution, with initial animation and simple textures. Chris did a wonderful job of articulating the skeletons and establishing the character animation. However, once we received the scene data we had to polish the animation, tweaking and smoothing motion and actions in conjunction with Robert's requests."
Under the direction of The Santa Monica offices animation supervisor, David Lombardi, a team of Maya animators continued with animation and later incorporated all new high resolution models and textures into the scenes. In addition they added new skeletons in order to guarantee continuity from scene to scene. . "We hand animated 63 characters," reports animation supervisor David Lombardi. "Over 28 shots feature multiple skeletons." Beaver translation software enabled the animators to efficiently translate all the necessary Maya data into Lightwave for lighting, texturing, and final rendering.
Radiosity rendering, which calculates bounced lighting, was done in Lightwave. "It's uncommon to use radiosity rendering in production," Lombardi notes. "Traditional CG rendering is faster, but radiosity rendering is much more accurate and realistic, especially for an outdoor scene with nooks, crannies and sword reflections, because it's what happens in nature." The shots were composited in After Effects.
The studio was also charged with the sequence's wire removals; the kids had been rigged for safety on a dramatic real rock formation as they battled the as-yet-unseen skeletons. "Seven of the shots were the gnarliest wire removals I've seen," reports Lombardi. "They were tough for even the most experienced artists." The camera moved on three axis changing the 3D perspective on the rocky promontory and making wire removals extremely difficult. For one shot that was crisscrossed with wires animators rebuilt an entire clean rocky terrain in 3D. It was tracked into the shot with 2d3's
Boujou software, and composited under the kids. The majority of the easier wire removals were done using Discreet's commotion while the more challenging removals were done utilizing the company's Discreet flame*.
ComputerCafe animators were assisted in their communications with Austin, Texas-based director Rodriguez by the use of QuickTime Synchro software developed by visual effects studio Hybride Technologies, in Quebec, which also worked on Spy Kids 2.
"Hybride licensed QuickTime Synchro to all the companies working on the picture," Domenic DiGiorgio points out. "We'd do a conference call with Robert in Texas, run the program, bring up a QuickTime of a shot that Robert would see on his screen. He could talk and draw on the frame, and we'd see it in real-time. It helped make communications 200 percent clearer." The files, which Rodriguez marked-up, were saved for future reference.
"Working on Spy Kids 2 was fun because Robert had such a strong vision and was so involved with the visual effects," notes Vicki Galloway Weimer. "Everyone on the Rodriguez team was professional, great to work with, and collaborative."
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