By IAN FAILES
Animating an object or character with the correct ‘weight’ is an assignment often entrusted to visual effects studios. This can range all the way from CG bouncing balls to digital humans and, of course, synthetic creatures. When those creatures are enormous – as was the case in Brad Peyton’s monster film Rampage – conveying just the right amount of weight is perhaps even more crucial.
Determining the exact right amount of weight can be ‘somewhat intangible’, according to Weta Digital Animation Supervisor David Clayton, who alongside fellow Animation Supervisor Aidan Martin, helped deliver three massive monsters for Rampage. Clayton has seen his fair share of creatures over the years, including Smaug from the Hobbit trilogy, and here he offers some thoughts on what makes a character seem to have believable weight.
Watch the trailer for Rampage
“Imbuing your character or shot with weight is kind of the holy grail of being an animator here at Weta Digital,” states Clayton. “What I’ve learned over the past 15 years is that with big creatures, they can move quickly, but they need some time to generate that speed, and they need some time to wash off that speed. So if they do stop suddenly or impact with something abruptly, then the ripple effect caused by that sudden stop needs to take place slowly. That’s what gives you the cue that it’s big.”
The monsters – a mutated crocodile, wolf and gorilla – battle in Chicago
“Imbuing your character or shot with weight is kind of the holy grail of being an animator here at Weta Digital.”
—David Clayton, Animation Supervisor, Weta Digital
For Rampage, Weta Digital was primarily responsible for three of the main creatures: George, an albino gorilla that is normal-sized until it encounters an experimental pathogen which causes rapid growth; Lizzie, a crocodile that is also infected and mutates into an immense reptile; and Ralph, a gray wolf which similarly grows out of control. They ‘rampage’ their way to Chicago, destroying buildings, vehicles and, mostly, each other.
For many Rampage scenes, the animators had to portray the creatures leaping and falling as believably as possible. What worked in each shot was often a matter of experimentation, says Clayton, but there are some tricks that the artists at Weta Digital rely on to help convey the right weight and force for CG characters like those in the film.
George the gorilla rampages in the streets of Chicago. Early motion studies done by Weta Digital helped establish the weight and mass of the character
“If [big creatures] do stop suddenly or impact with something abruptly, then the ripple effect caused by that sudden stop needs to take place slowly. That’s what gives you the cue that it’s big.”
—David Clayton, Animation Supervisor, Weta Digital
“We often display a little falling gravity cube in our shots,” explains Clayton. “If a character is jumping or falling, you just put in a gravity cube that has a perfect parabola that’s been calculated to work with gravity. So if that’s arcing through your shot with legitimate gravity, and then you have your character jumping or falling, you get a sense of, ‘Oh, he’s dropping too fast there’, or maybe there’s not enough acceleration towards the ground.
Early motion studies of the characters, including for George at his different sizes, helped inform the kind of movement and weight that would ultimately be required. “I jumped in,” says Clayton, “and did some motion studies of George leaping off cars with an indicator of gravity so I could get the client on board with the idea that once he gets bigger, when he jumps and lands and moves through frame, it’s going to be slower.”
George lines up against Lizzie in Federal Plaza. Weta Digital’s CG characters also interacted with simulated debris from an earlier tower crash.
“We often display a little falling gravity cube in our shots. If a character’s jumping or falling, you just put in a gravity cube that has a perfect parabola that’s been calculated to work with gravity.”
—David Clayton, Animation Supervisor, Weta Digital
In one Rampage scene, the monsters have felled Chicago’s Willis Tower and are continuing the fight in Federal Plaza when George grabs a construction crane out of the rubble and swings it towards a charging Lizzie.
Says Clayton: “We had to make sure that the momentum of the crane as he’s swinging it, slowly built up speed until it was going fast enough to actually hit Lizzie’s face. When it does, that energy has to transfer from the crane to Lizzie’s head. It’s almost like those little Newton’s cradle swinging balls, but on a much larger scale. You’re just observing the mass, the energy.”
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