You've met Jacob Black and his pack of werewolves before, but you've never seen them like this. Fans were first introduced to the hirsute shape-shifters last November in "The Twilight Saga: New Moon," but when director David Slade took over directing duties from Chris Weitz on "Eclipse," he brought with him a new vision for the wolves.

And it was up to visual-effects legend Phil Tippett — his studio engineered a dizzying array of hits, including "Cloverfield," "Pirates of the Caribbean: Dead Man's Chest" and "Men in Black II" — to translate Slade's vision into computer-generated effects worthy of the big screen. With just hours to go until the midnight opening of "Eclipse," Tippett called MTV News and gave us a behind-the-scenes look at these cinematic wolves.

The Wolves Have New Fur, Eyes and Behavior
Weitz requested wolves that had more of a rangy look to them, with matted fur and eyes that more closely resembled human eyes than wolf ones. By contrast, Slade wanted his wolves just a bit more, well, coifed.

"They weren't supposed to look like poodles, but [Slade] wanted them a lot sleeker looking and with shinier, shimmering coats," Tippett explained.

Slade was also adamant that the "Eclipse" wolves revert to the wolf eyes you might see in nature. But it wasn't just the wolf pack's physical attributes that got a makeover for the third installment. Tippett and his team were also directed to adjust the wolves' overall behavior.

"The 'New Moon' wolves, we played them as heroic sentries," said Tippett. "When the wolves met the humans, we attempted to make it appear as though the wolves had a center of conscience that was definitely human. And David really wanted to play it that the wolves were far more primordial and much more wolflike. The wolves became less sentries sent from God and a lot more twitchy, uncertain, fairer animals."

Perhaps the biggest similarity between both films' wolves, however, is that neither set actually has genitals — a compromise necessary to secure a PG-13 rating. "We just deal with it by putting extra fur down there," he laughed.

Taylor's Wolf Is Sad
Tippett and his crew spent countless hours perfecting each member of the wolf pack, but obviously Taylor Lautner's wolf receives the most screen time and thus required the closest attention. Specifically, they had to capture Jacob's unrequited love for Bella while he was in wolf-form.

"Through non-language pantomime on the wolf's part, he had to appear to be engaged and try to make his expressions telegraph the tragic love that is their relationship," Tippett said. "So there is a sad kind of a longing and protectiveness that we try to imbue him with."

To get the look right, crew members traveled up to a wolf preserve, and actually got into pens with the 200-pound animals and sketched out what they observed.

"I'm a huge advocate of that. Anytime you can get close to an animal, that's the closet model you can find," he said. "And the animators are cast just like actors. Certain animators are really strong on action and there are animators that are really strong on the emotional moments. And the animators strong on emotion were the ones creating the emotional response of Jacob's wolf."

The Vampires Fought With a Potato
Since the wolves are entirely CGI creations, the actors are presented with a challenge: how to interact with — and often fight hand-to-paw against — imaginary beings. What's more, they had to do all this in such a way that would allow Tippett and his animators to plug in their digital creations. The solution they hit upon was what came to be known as the "potato."

"We came up with this object that we called the potato," Tippett said. "And the potato was roughly a very rudimentary wolf form that was kind of like a big pillow that matched the dimensions of the wolves without hair. And those would be set on location by the special-effects department, and they would rig these potatoes with wires so they would hang and we would be able to manipulate them in a way that we knew later on we would be able to match with the wolves in a realistic confrontation."

Taylor Dressed Up in a Gray Leotard
Alas, the potato wouldn't always suffice. For one scene in which Jacob's wolf nuzzles up against Bella, filmmakers required something just a bit more lifelike than a big pillow.

"David was very insistent that Taylor actually perform with Kristen, and so he had the wardrobe department make up a gray leotard and a hoodie that Taylor wore, and he would kind of crouch down and try as best he could to fit that space where we knew later the wolf would be," Tippett said. "And Taylor could remain in character and ensure that the performance was a performance based on contact between two performers, not just Kristen talking to a golf ball or something like that."

Fantasy Trumped Physics
In the climatic fight scene, when the wolves take on a newborn army of vicious vampires, the effects team found itself in a conundrum: How could a 1,200-pound wolf and a 180-pound vampire get into a realistic fight?

"We have to be true to Earth's specific gravity in the performance work to make it seem like the wolves are really there," Tippett said. "But if a 1,200-pound object is slamming into a human being at 30 miles an hour, it's going to have pretty severe consequences. And so there are these scenes where it's like, 'Oh my God, how are we going to pull this off?' "

Their solution was to sprinkle a hefty dose of magical realism into their physical calculations.

"David's justification for it was, 'OK, the newborns are made out of some material that increases their mass and that they are closer to 500 pounds," Tippett said. "The actors didn't actually play it like that — I don't think they ever told them that because they didn't start walking around like the Hulk or anything — but what it did is gave us an excuse to be able to choreograph these things. So when a wolf runs and attacks and slams into one of the newborns at the tail end of the third-act battle, we have a performance justification for how that works. That was actually planned out and made sense and didn't look stupid."

Check out everything we've got on "The Twilight Saga: Eclipse."

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