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January 2018

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Page 26 of 43 25 POST JANUARY 2018 VFX FOR SPOTS VFX FOR SPOTS phy to understand exactly how they behave, from a single feather's movement to how a clump of feath- ers respond to the bending of the neck." The artists created the feathers using a system that was built by MPC London's creative director Diarmid Harrison-Murray, based on a Side Effects Houdini fur setup the facility evolved to create state-of-the-art feather software. "It's robust and flexible tech that we can extend and adapt for different jobs," says Christian Bohm, senior technical director on the job. As Bohm explains, the system had to be devel- oped slightly for this project, since the feathers of a stork are unique in the way that they create a very closed and smooth surface in one area and clearly visible, separate feathers in other areas. He says, "We added a way of bending the feathers slightly, for example, so we could create a softer look for the overall surface where needed." The Houdini fur system enabled the team to craft the feathers "down to every single strand," says Bohm. The system was separated into two parts — the body and the wing feathers, which are both fairly different in the way they behave. A lightweight representation of wing feathers were animated within Autodesk's Maya, and then replaced at render time with "fully-fledged" feathers in Houdini, before being rendered in Side Effects' Mantra. "We had around 100 feathers for both wings, with ap- proximately 1,000 strands per feather," Bohm says. The body, on the other hand, is groomed on the geometry level; thus the feathers were created according to the setup. This enabled the group to craft different shapes and appearances of feathers that could then be painted on the geometry for combinations and variations based on the painted masks. "This means it creates mixed styles of feath- ers where the masks of different types overlap," Bohm says. "Combined with some procedural vari- ation, this system basically makes sure that every single feather is unique." Due to this large quantity, rather than ful- ly simulating the body feathers, the artists had to "cheat" their movement. "Simulating around 25,000 feathers with 500 strands, all colliding with each other, is quite an undertaking, and you end up with a lot of weird movement," says Bohm. "That volume was simply too high to achieve the result we needed, so we were able to add some noise to their bending and got to almost the same result as a full-blown simulation." The wing feathers, however, were different. They were simulated on top of the animation, as there were fewer feathers to deal with on this part of the bird's body. Rendering the fine-feathered bird proved especially difficult. "Frankly, we thought a stork shouldn't be too complicated, since it only consists of soft, white feathers — how hard can that be? Well, we were wrong," Bohm says. "We needed a lot of time and many rounds of experimentation and reviews to nail the distinctive look of a stork. The character required some really subtle tweaks and changes to achieve its overall softness, while keeping the amount of feathers, and their individu- al look, realistic." It wasn't enough for the stork to look real; it also had to move in a realistic way — from the flapping of its wings and landing on the ground, to the sub- tlest twinkle in its eye and hesitancy when crossing the road to the neighboring home. "Xavier came into the studio and acted out, shot by shot, how he wanted the stork to behave, from imperfections in its movements, almost clumsy, to the contrasting graceful and delicate movement when the baby is placed on the ground, creating an intimate connec- tion between the baby and the stork," recalls Bryan. To give the stork's flight cycle a more natural and irregular look, the team developed a technique within Maya's animation layers that allowed them to adjust how much energy they put into the body and wings by simply adapting the weight of each layer for when the bird is in flight. In the commercial, the stork is given the import- ant task of delivering a baby. Key to delivering a convincing performance was getting the weight of both the stork and the baby correct. After all, a baby wrapped in cloth hanging from a stork's beak is not something you can find real-life refer- ences for. So, the animators had to contemplate how this extra weight might affect the motion of the stork and then incorporate that into the scene. Unlike the stork, the baby is real. "We always try to follow the rule that CG should only be used when necessary; so the baby was real," Bohm says, noting there would not have been any benefit to creating a CG baby. "Quite the opposite, actually, since mixing reality and CG usually is way more believable that relying on pure CG alone." Madeddu concurs. "We all think the same thing when we see a full-CG baby in a movie: 'That's not quite right, is it?' You never know what it is, but your brain twigs that there's something wrong," he says. "Babies, probably more than fully-grown humans, are one of the most challenging 3D cre- ations to overcome." MPC's team came up with a creative solution: The production's art department created a rig on set with a dummy baby filled with sand, all wrapped up in a bundle cloth. This was then filmed being placed on the doorstep — to provide reference, as if there were a real baby inside. "The tricky bit was when the stork puts the baby down at the doorstep of the house — in that moment we switch from a full-CG bird with a CG bundle to the real footage, which required very accurate comp'ing with the stork's beak," Madeddu adds. MPC relied on more than 70 artists in 90 days to craft this Trailblazers spot for Heineken.

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