July 16, 2007

Framestore CFC Creates Kreacher and Creatures for Harry Potter Film

London - Harry Potter and the Order of the Phoenix is Harry Potter's fifth cinematic outing. The film is a Warner Brothers Pictures production, and is directed by David Yates. It opens in cinemas worldwide on July 13th, and Framestore CFC is again along for the broomstick ride. This time around the company's CG contributions included a herd of centaurs, a sinister house-elf named Kreacher, and, for the first time, the film's title sequence.

Much of the wizarding world, including the Ministry of Magic, is in denial about Lord Voldemort's return. The Order of the Phoenix is a group formed by Dumbledore to resist and counter Voldemort. Cornelius Fudge, Minister for Magic, suspects that Dumbledore is using these claims of The Dark Lord's return as a means to overthrow Fudge as Minister. In retaliation, a new Defence Against the Dark Arts teacher is appointed by the Ministry, with the real aim of monitoring and controlling Hogwarts. This new teacher, Professor Dolores Umbridge, imposes strict new teachings and rules, forcing a group of students, under Harry's tutelage, to form a club by the name of Dumbledore's Army...

Heading the team for Framestore CFC was veteran VFX supervisor, Craig Lyn. "We have made a name for ourselves producing creatures with real character for the Potter films, creatures such as the Cornish Pixies and Buckbeak the Hippogriff" he says. "The centaurs and Kreacher gave us a chance to build on this reputation, both technically and artistically."

The centaurs of J.K. Rowling's vision are not the cute, prettified creatures of Disney's Fantasia, but rather fierce, mysterious beast-men, in whom the human half leans towards the caveman in appearance. They feature chiefly in one key sequence in Harry Potter and the Order of the Phoenix -- an encounter with Harry, Ron, Hermione, and the appalling Professor Umbridge in the Forbidden Forest. During a tense face-off, one of the centaurs is hurt by Professor Umbridge, who subsequently finds herself being carried off into the woods by the enraged half-men.

"Purely from a technical point of view, there were a number of aspects to the centaurs that Framestore CFC hadn't tackled before," says Lyn. "Skin moving over muscle, the muscle dynamics and the dynamic hair simulations, for example. Not only that, but there were up to 12 of them onscreen at once."

As originally scripted, the centaurs had a great deal of dialogue, and so were the focus of much of the team's initial development work. A huge amount of effort went into pushing the new skin and muscle methods for doing overall bodies, with particular reference to the facial aspects. Ultimately, changes to the script during production meant a much reduced -- and virtually silent -- role for the centaurs.

"It was sad for us," says animation supervisor Max Solomon, "but it made sense in terms of the film -- they've got so much story to tell in just a couple of hours."

The team strove to create a whole animal, rather than just a man with a CG horses hindquarters added -- the approach taken in some other films. “We wanted to make it feel like a man was thinking and making the horse part move," says Solomon. "One of the trickiest shots is where Bane -- one of the centaurs -- is caught by a rope, rears up, and falls to the ground. We had some rearing horses but the mechanics of a horse rearing is different -- what they do is throw their heads down low in anticipation, and then throw their heads up. So we had to make it feel like a man jumping, keeping the back very straight, and yet like a horse as it lay thrashing on the ground."
CG supervisor Ben White concurs. "The centaurs presented a double challenge," he says, "trying to combine belevable human and horse torsos was a great deal harder than doing either one separately. When the centaurs move around they have to move in a convincing horse-like manner, and yet still have the characteristics of a human -- which is very tricky stuff to do, both in terms of animation and the movement of muscle and skin. To really push the realism of the characters we developed a new method for doing sliding skin over underlying volume. We prototyped the skin and muscle behavior in Houdini, then our R&D department developed this into an in-house Maya plug in, which we used to actually run the shots.”

Kreacher, whom Harry encounters briefly at Sirius Black's house, is an elderly, somewhat sinister house-elf. Craig Lyn is particularly proud of the work that went in to winning the job of creating him. "The number of shots Kreacher is in isn't huge, but at the same time it's a tricky bit of work because he's a humanoid character who acts, delivers lines and fills the whole frame,” says Lyn. “Three of the guys on our side decided that they really, really wanted a shot at him. On their own initiative they built, modeled, textured, and did a turn-table of his head and sent that off to the client. And it was that work which won us the gig."

Although he delivers just a few lines, Kreacher's words are loaded with meaning, and his body language is similarly freighted. Says Max Solomon, "You tend, as an animator, to animate -- to put in the traditional, slightly heightened stuff, with the creature hitting its marks perfectly and so forth. But we soon realized that that was not what was wanted here. So we worked against our instincts, and it was quite strange. We kept thinking he's not really doing much, he's not moving, he's not really acting -- but actually that does feel more real. A little hunchbacked old man doesn't actually move or gesticulate a lot, so doing almost nothing was the right choice."

Technically, says Ben White, "We took an entirely muscle-based approach to Kreacher's facial-animation system, extending the functionality of the tools we designed for the centaurs and taking them even further, to give him skin that's appropriately soft and stretchy for such an elderly character. We filmed actor Timothy Bateson as he sat in a chair and did his vocal takes, using his facial expressions and mannerisms as reference (although no motion capture was used), and these were incredibly useful for the facial performance. But the actual combination of body language, stance, how Kreacher moves around and how he reacts to Harry -- that was entirely the creation of our animation team. This subtlety of animation, combined with the sophisticated skin shading and really believable eye lighting gave us something I'm really proud of. It's a beautiful, understated little performance: you feel that you can really see his mind in his eye, like he's a living being."


Harry Potter and the Order of the Phoenix

A Warner Brothers Pictures production

Directed by David Yates


For Framestore

CFC Visual Effects Supervisor Craig Lyn

CG Supervisor Ben White

Animation Supervisor Max Solomon