Rampage: a creature tale

By Ian Failes

Rampage, loosely based on the Midway video games of the 1980s, is a classic movie about monsters, and Weta Digital handled three of them. First, there’s George, an albino gorilla cared for by Davis Okoye (Dwayne Johnson) until a rogue company’s experimental pathogen causes the animal to grow – massively. Other hapless fauna become infected too, including Lizzie, a crocodile from the Everglades, and Ralph, a gray wolf from Wyoming. Together these beasts rampage their way to Chicago, a city the filmmakers had to partially destroy as the monsters rip apart buildings and ultimately take on each other.

Meet George

Perhaps more than most visual effects studios, Weta Digital was an obvious contender to handle a majority of Rampage’s visual effects. The story would begin with a family of gorillas, and George, and Weta Digital’s experience on the recent Planet of the Apes films, of course, prepared them in so many ways, and would also serve as a launching pad for the crazier creature scenes later in the film. This meant overall visual effects supervisor Colin Strause could easily lean on the visual effects studio’s expertise in the area of digital apes.

As it had been on the Apes films, the normal-sized George would be approached with an on-set performer in active marker motion capture gear being captured live on set. Jason Liles was chosen for that role. “Jason is about 6’10,” notes Weta Digital visual effects supervisor Erik Winquist. “You put arm extensions on him and he’s actually good gorilla size when he’s squatting. As George grows to be more than 40 feet tall, a hybrid approach of some motion capture through to pure keyframe was adopted.”

Opening scenes take place at a zoo, actually a planted bamboo forest in a university outside Atlanta. “It allowed us to set up our motion capture cameras in a similar way to what we had done on the Apes films where you just place them around the scene,” explains Winquist. “And it allowed the four human actors to basically play off the gorilla performers in a very natural way. The eyelines are there, they can riff off of each other, the performances come off very natural because of that, so it was an obvious choice to do. We also were lucky to have the daughters of Terry Notary, who is well known now as being one of the motion coaches for all the Apes films and Avatar. And they’re probably the best trained young, small ape performers in the world at this point.”

To animate normal-sized George, again a similar workflow to the Apes films was employed. The facial and body capture process goes through Weta Digital’s tried and tested pipeline. Motion editors use Nuance for body motion, while the studios facial animation solver is written in-house. The motion data, and any fine tuning or keyframe animation that the facial animators do, is applied to the character via Weta Digital’s Koru facial puppet. This is a GPU-accelerated full resolution version of the character’s face that the animators can work with in real-time.

While there were similarities between the Apes films and the approach to George, the former films ultimately featured primates that were in many ways more humanised, whereas normal-sized George is intended to be a real gorilla . “So,” says Weta Digital animation supervisor Aidan Martin, “we started with the same facial capture system except we started to go away from that. On Apes, the performance is the performance and we have to stick to the performances that the director and the lead actors really worked hard on. Whereas with on Rampage, we had the freedom to go off the performance and at times I would not necessarily enhance the performance but just have different options, different directions. There were times, too, where they were shooting a lot of pieces but not necessarily putting them together in order.”

George’s design was based on several concepts, including by Aaron Sims Creative and Weta Workshop (both worked on the other creatures, too), and on real gorillas. Brad Peyton was presented with a selection of real-world animals from zoos in San Diego, Atlanta and elsewhere. “He picked this gorilla called Winston who just happened to be the model for one of the other gorillas from War for the Planet of the Apes,” says Winquist. “So the challenge ultimately became making a character that was actually unique to this movie that wasn’t stomping on or feeding IP from another movie that we just finished. And also it was about coming up with something that had maybe a bit more of a sympathetic look to it because we really needed to cement this really solid relationship between Dwayne’s character and the gorilla.”

After Liles had been cast, mock-ups of the actor’s face and that of Winston were drawn up. “The thing we’ve certainly learned over the years is the more that we incorporate prominent features of the actor who’s playing the character into the character, the more you really start seeing flashes of that actor come through,” states Winquist. “Jason has these expressive eyes and he’s got a fairly prominent jaw. So incorporating some of those features into this new hybrid gorilla further pushed him closer to Jason. There were moments in the opening scene where George is climbing around where you look at Jason and you look at George and you go, ‘My god, Jason’s in there.’”

Weta Digital’s creatures team was responsible for modelling and rigging the gorilla puppets, and then taking the published animation and using the studio’s proprietary tools to simulate muscle, flesh sims and fur. Ape fur or hair was yet another thing that had been previously solved by Weta Digital, thanks to a combination of its Barbershop and Wig hair simulation and grooming tools, and proprietary renderer Manuka. The challenge on Rampage, though, was that George was an albino gorilla – with white fur. With Snowy from Tintin and Winter from the Apes films, Weta Digital had tackled white fur before, but as Weta Digital visual effects supervisor Thrain Shadbolt notes, “white fur tends to basically take longer to render. It takes longer for the path tracer to resolve to a point where the image is noise free, and it basically means that the white ape is just tougher to render than a dark ape and takes longer to get a clear image.”

George and Davis communicate via sign language (American sign language), which animators needed to ensure were realistically portrayed. Some artistic licence was taken, especially to convey clear meanings. “There’s a moment where Dwayne Johnson’s telling George that they’re going to go ‘kick some arse,’” relates Martin. “Dwayne signs in a certain way and then we had a very similar sign that was something like a very similar sort of punching together which meant destruction. And then originally we had George doing the signs literally for ‘kicking’ and ‘arse’, but, of course, we needed to make that into destruction, too.”

“For the signs,” adds Martin, “we looked to video reference. “There’s a couple of good websites where you can just type in a phrase and it will interpret all the words for you and give you a compilation of video reference of someone doing the signs.”

Meet Elder Gorilla (just briefly)

Weta Digital’s prowess in creating digital gorillas extended to one character who had the briefest of appearances in Rampage, when an elder gorilla walks through an early scene in the film. “We were on set,” recalls Winquist, “and there hadn’t really been a discussion about this elder gorilla and then Brad’s like, ‘Yeah, and we’ll have the old man gorilla come through here.’ Colin and I are looking at each other like, ‘What is he talking about?’”

A stunt performer acted as the elder gorilla for the shot, with further motion capture done back in Wellington. Then Weta Digital went through its usual workflow to bring the character to life. “The funny thing is, we built this hero level character that appears in only one shot, and he’s my favourite gorilla of any gorilla that we’ve done,” says Winquist. “He looks like some sort of gorilla version of Grandpa Simpson. He’s got this really amazing crest, like all this like gnarled skin going up. And he’s got this fantastic look on his face.”

“We actually tried to put him in more shots,” notes Martin. “There’s a shot where they’re all sleeping and we put him in the background laying on his back, snoring away. But they didn’t really like that. It’s like, ‘Aww, poor old man gorilla.’ Because they get woken up and we had him in the background being woken up, but being too out of it to get up. And so he’s sort of flailing around trying to roll around to get up while everyone else is up and zipping away. I’m sorry we couldn’t have him in more shots.”

George gets big, really big

As the pathogen ingested by George takes hold, he grows rapidly. Until he is enormous, Liles continued to perform George in motion capture gear, this time with a pole fastened to his back or helmet that rose above his head as an eyeline mark for the actors. “This allowed us to still capture his performance, most importantly, facial performance, while he was in the scene with the other actors, and gave the other actors something to focus on which represented where his character’s eyes would eventually be,” says Winquist.

The obvious immediate challenge for Weta Digital’s team was how then to approach the animation of the same character but in large form. Martin says they considered that a bigger character does not move as fast. “When he gets 40 feet, his proportions change and his arms are getting longer. So he goes from being able to do legitimate jumps to being able to do absolutely unbelievable distances.”

“For instance,” continues Martin, “there’s a really great shot of George scaling a building using two hands and a jumping up motion. We used chimp reference of when they’re swinging from vine to vine through the trees – we’ve actually got a reasonably extensive library of motion from previous movies – and we’re still re-using Terry Notary’s performances from the Apes films.”

Indeed, a larger, crazier George afforded several ‘rampage’ moments for the character. Some of these were even inspired by early motion tests done by Weta Digital. “The animation team, they thrive on that stuff of coming up with cool gags,” says Winquist. “They’ve been raised up under the tutelage of Peter Jackson, who just wants to see the next ‘just come up with cool stuff’. So they’re really great at playing around like that.’

An example is when George rips the facade off of an gaming arcade building, which came out of early motion studies done by animation supervisor David Clayton. “I just started having some fun having him busting through the cityscape, pulling the front edges off buildings, barging into things,” Clayton says. “You just let the character loose in a scenario, and you just start animating and see what happens. It’s almost one of the most enjoyable parts of the process: ‘What does George do when he’s completely crazed, and he’s in the city, and he’s presented with all this stuff? What does he do?’ Now it’s one of the trailer beats, and in the film.” (read more about this shot in ‘Rampaging!’, below)

Even though George’s dramatic growth gave Weta Digital many moments to show him tearing up Chicago, there remained times when they needed to continue to communicate his emotional connection with Davis. Such is the case in the film’s conclusion where George has been able to dispatch Lizzie (who has earlier disposed of Ralph) and is close to death. In fact, in a payoff to an earlier scene, George fakes his death so that he can ‘give the finger’ to Davis who believes the gorilla has been killed.

Johnson and Liles performed the main beats of that scene in an Atlanta studio backlot, with Liles high up in a cherry picker and Johnson acting at ground level – replicating the framing from the final scene. “It was actually a pretty crazy shoot,” says Weta Digital visual effects supervisor Stephen Unterfranz. “We had the set there with an island of debris, greeenscreens, and then there was this really aggressive lightning and thunder storm, and we all had to take cover. We came back out to shoot and then it’s really hot, and Jason was not in the capture suit at this point, but he’s there to interact with Davis, so Dwayne has somebody to act with. Jason is up in a bucket with an umbrella from the heat. There’s a tennis ball as well for George’s eyeline, and Dwayne is just acting to this ridiculous scenario with this guy, with a green screen behind him, and he’s in a bucket with an umbrella. It didn’t seem like there could be an emotional connection, but there was.”

Indeed, by that time in the shoot, the two actors had already established their relationship on-screen, making the intimate moment all the more believable. Weta Digital had to take the on-set performances and add to the emotion. “You can tell George is about to die and The Rock’s getting emotional and George is getting emotional and there’s some nice little sign language moments of, ‘I saved you…’” says Martin. “It was a tricky moment to pull off, and then changes when it’s revealed he is just joking.”

Letting loose with Lizzie

Lizzie, the Everglades crocodile, makes her way via the Mississippi River and other waterways to Chicago, seen only in a few brief splashes and then spectacularly revealed as an enormous monster leaping into the cityscape and later climbing and destroying buildings. While keeping the overall crocodile feel, Weta Digital had to add extra attributes such as tusks, dilophosaurus gill flaps, a spiky tail and a ‘cancerous-looking’ tongue, much of it used in threat displays. “She spends a lot of her time roaring, so we went to things like horrible cigarette packet warnings for her tongue, for example,” says Winquist.

Lizzie’s big reveal occurs with a 270 degree helicopter shot around her – which began as a live action plate – as she emerges from the Chicago River. Describes Shadbolt: “She comes up out of the water and underneath a tourist boat, flips that over, there’s a crowd of digital doubles that get tossed into the water, and then she kind of claws her way up onto land and we swing around and we see her roaring. That was probably one of the more challenging shots I had on my slate.”

Aside from the character animation, Lizzie’s entrance also involved a great deal of water and effects simulation. Weta Digital tried some new approaches for the project. “Our water lead, Kelvin Cai, spearheaded a new workflow that allowed for a lot of art directable changes and much faster simulation times than with previous large-scale water simulations,” says FX supervisor Jonathan Nixon.

“We started with a primary water tank simulation with Houdini’s Flip Fluid solver. Within that simulation, we made sure to couple Lizzie’s interaction with a wind force model that was specifically built to help simulate large scale drag in within the Chicago river. This addition really helped sell Lizzie’s size and weight directly into the primary simulation. We were able to quickly turn around the primary simulations to give animation a guide as to how fast Lizzie should be moving as well as how deep under the surface of the water she should be in order to achieve a proper and realistic water solve.”

“With our primary solve in place,” adds Nixon, “our water TDs then added a variational viscosity solve to achieve looks for silt and mud within the Mississippi and Chicago river beds. We then generated simulated secondaries with a custom white water solver that was based on phase-change, which allowed for a free transition between spray, foam, and bubbles. The bubbles were then generated and rendered as volumetric aeration and then blended with the primary surface. This new workflow still allowed us to render using our proprietary software but gave us very flexible and art directable iterations which can be very difficult when dealing with creatures this size.”

Animating Lizzie – the largest of the three creatures – required an exploration of walk and run cycles, and even climbing animation tests. “We knew when Lizzie’s climbing up that building, that’s the tough sell, getting the physics of that looking good was going to be challenging,” remarks Clayton. “So we just focused a lot of effort on that early on in our motion studies of her climbing, her barging through the building, and so on, just to explore that, to start to percolate that idea a little bit with a little bit of lead time, so when it came time to animate the shot for real, we sort of have a pretty good idea of how to sell it.”

Reference of enormous real alligators or crocodiles was sourced, but did not always prove useful. “We did find a reference of a crocodile climbing over a fence, but it was just comically ridiculous,” says Clayton. “You really just have to have a handle of what feels cool and feels big. Looking at reference helps, because it gives you some interesting kind of variations on how you’d expect something to actually happen, and you can weave that in, but at the end of the day, you’ve got a shot, and you’ve got an idea you need to get across. You just want to animate that so the audience gets it.”

At one point in the film, George returns to the side of Davis, and teams up to take on Ralph and Lizzie. First, though, Lizzie rips Ralph’s head off and eats it. “Our animator was able to find a really great National Geographic reference of a crocodile just swallowing down a lump of flesh,” says Clayton. “So we just observed that and animated it just like that. It just broadcasts to anyone who’s ever watched a nature documentary.”

Realising Ralph

Ralph is Weta Digital’s third large-scale monster, and takes the form of a mutated gray wolf. He starts his journey to Chicago from Wyoming, taking out a group of mercenaries (and their helicopter), and a tour bus, before wreaking havoc in the big city with the others.

“Ralph was probably the most bizarre of mashups,” admits Winquist. “You’ve got a wolf that has lost most of its fur, it’s covered now in what looks like rhino skin armour, it has porcupine quills and wings. We all had that same reaction that Dwayne does in the movie when he says, ‘Of course the wolf flies.’ On paper is like, ‘Whoa, cool idea.’ Then you go, ‘How are we going to do this?’ Because you look at the physiology of a canine versus the physiology of a sugar glider or a flying squirrel, which is basically where some of this concept was riffing on. And a dog can’t do that. They’re not skeletally built that way. So we looked at a lot of ways to keep this plausible, and at the end of the day you go, ‘Wait, this is a movie based on a video game, let’s just bring the arms up.’”

The helicopter scene involved the mercenaries first being picked off by Ralph in a forest before he leaps into the air and destroys the chopper as it tries to escape. “There was a real helicopter used on set for reference, but the attack and bringing down is all-CG,” says Shadbolt. “The director wanted a lot of things to happen, ripping it with its snout and tossing people out of it and the blades are hitting him and breaking off, and before it hits the cliff he’s going to jump off in mid-air. So, trying to make all of that look credible and physical is obviously the animation challenge first of all. And then to make the physics of all the additional secondary effects look credible on top of that – we had the effects department come in and do stuff crumbling off the cliff, rocks falling away and shrapnel from the helicopter getting damaged and crumbled.”

Ralph’s mean-streak continues in Chicago, including for a shot in which he bounces off buildings and bursts back through one, wings at full span. “A scene that like,” says Clayton, “required interaction between animation and the effects team. We knew he’d only actually make a small footprint coming out of the building, which is how’d you bust through something, you can’t bust through something with too much of a silhouette. Then we just made sure that he was just bursting through with a good velocity, and that as he jumped, he had realistic gravity until he spreads his wings, and then that gravity can slow down a little bit. He was jumping right towards camera, too, so there’s often a problem when a character is aimed directly at camera in animation, it just looks very foreshortened, and simple, and just not pleasing to the eye. So we swung his hips out a bit, and tried to get some variety in the shapes of his arms and legs.”

Scouting, shooting and surveying Chicago

When the monsters hit Chicago, they tear up the city and destroy a number of buildings. Weta Digital would need to incorporate their digital characters in many street scenes, as well as replicate several landmarks. Interestingly, although the monsters do ‘rampage’, they don’t destroy every building in the city, and Weta Digital was able to pick and choose which parts to replicate digitally and rely extensively on live action plates. To do that required a co-ordinated surveying approach to the city, led by Unterfranz and Ryan Cook as on-set visual effects supervisors, who firstly reviewed previs to see what areas might need capturing, before launching into the survey process.

Unterfranz began with a desire to LiDAR-scan some of the key areas of Chicago in a unique way. “I’m from Chicago originally, and I have an old Jeep Wrangler in the garage, in my dad’s workshop. I had the bright idea to go and get my Jeep, and because it was summer, we took the top down and we ratchet-strapped a LiDAR tripod to the Jeep. We thought we could move it early in the morning and just park every 50 metres to fire off a 2-minute scan, and then move again. The thing is, the tolerance that the on-set guys need in terms of the LiDAR equipment being level and in terms of it being continuous so that they can stitch the whole thing together, it’s within a matter of millimetres per hundred metres.”

“Any kind of movement on the road would upset the suspension of the truck enough to throw off the survey,” says Unterfranz. “We scrapped that and the guys did it on foot, and they just moved the LiDAR down the street. I think it’s probably the largest city survey we’ve done. There’s also probably thousands if not tens of thousands of photographs of Chicago, HDRs, matte painting reference, texture references, skies and building photos.”

A showdown between the creatures takes place in Federal Plaza, another location that was heavily surveyed. “I think in two and a half days, we did something like 56 different setups, times three or four shots, plus tile sets for each of those setups,” describes Unterfranz.

Shooting the Chicago scenes then involved actual plates filmed in the city, and on a backlot and sound stages in Atlanta. Various ‘islands’ of debris were created, which Weta Digital would use as a base and then expand upon. Knowing they would need to frame for giant monsters, the production used “crazy telescopic poles with orange tennis balls on them,” says Unterfranz, “as well as simply counting the stories of buildings to work out the correct heights.”

For a number of key shots, such as Lizzie’s arrival into Chicago, aerial plates were required. Winquist praises aerial coordinator and pilot Frédéric North for being able to fly a helicopter expertly over the city. “There’s that one shot in particular where we first see Lizzie come out of the water, the big 270 degree orbit around the bridge,” outlines Winquist. “I’m looking around like, ‘There’s no way the city’s gonna let him fly a helicopter and do this path.’ Because he winds up in the air and he comes down almost to street level. And he did it. It’s some of the coolest aerial photography I’ve come across.”

Winquist also experimented on Rampage with using a flight simulator as the baseline for the motion of a number of helicopter shots and for a scene of an A-10 Warthog attacking the creatures. “The theory was, ‘Well, we’ve used this methodology for characters where they are motion captured and this gets modified and tweaked by animation just to the fit the constraints of the shot. Why can’t we do that with a flight sim?’ And it worked out surprisingly well as a, ‘Here’s some library motion that animation could grab.’ Some chopper shots tend to get brushed off as, ‘Oh it’s just a helicopter,’ but when you really look at what’s going on with the mechanisms there’s an insane amount of complexity. Well. if we can just capture that and not have an animator have to think about how they need to key frame it, then that’s a good thing.”

“Erik saved that data for us, and it was effectively like motion capture information for vehicles, for planes and helicopters,” adds Clayton. “It was really great, because just as when you motion capture performer acting something out, you get all those nuances, and weight shifts, and realism that you would never be able to animate. The same holds true for planes and helicopters. You wouldn’t think so, but just the nuances of movement that you get, little wobbles and jerks, and when a helicopter moves forward, you know it tilts before it travels. He also recorded us all the way the blades, the helicopter blades, handle cyclic pitch, and different values on them as the helicopter’s flying. Really amazing stuff, I learned a lot about it, and we got it all for free.”

Rampaging!

The movie is called ‘Rampage,’ and that’s exactly what the monsters do as they get to Chicago. They rip apart vehicles and buildings before climbing the Willis Tower. At one point, George rips off the front section of a Dave & Buster’s restaurant and arcade. This was a shot that came out of David Clayton’s early motion studies for the character.

“The director just responded to the explosive power,” says Clayton. “Just complete abandon about the ramifications. It’s like, ‘Well, I’m gonna take it to the next level and just rip the front right off it.’ It’s also a little bit less obvious than just punching through a building, or just smashing something.”

After the actual shot was animated, Weta Digital’s FX team helped enable the extra destruction. “When I first saw the Dave and Buster’s building shot from one of the animation motion studies, I knew this project was going to be a lot of fun for our FX team,” says Nixon. “We tested a couple of different constraint-building workflows within Houdini’s DOPs, and while those were initially promising, we needed to retain more of the animation driven motion to get the best results. We came up with a solution that allowed us to couple those rigid simulations with an animation guided solver that would evaluate whether an object should be simulated. Based on these rules, objects that passed this test became rigid body simulations, while the others would follow the original animation.”

“This workflow allowed for more flexible and art-directable results since the animation keyframes were still the backbone of our motion,” adds Nixon. “Our artists were able to generate secondary bending of facade, fracturing of windows, and generate secondary destruction for the building interior, debris, dust, etc. without changing the motion or positioning of George’s interaction.”

The ultimate impact of three over-sized monsters tearing through Chicago is the felling of the Willis Tower (which the creatures climb) and the destruction of buildings around Chicago’s iconic Federal Plaza. For that side of the action – especially the tower – Weta Digital’s FX department was tasked with developing a set of destruction simulations.

The tower’s fall begins with monsters climbing it in their search for the beacon. Effects simulations aided in showing windows smashing and debris coming off of the building. “Then,” says Unterfranz, “there’s the big event of Lizzie burrowing through the building. We’re outside on the helicopter shot of Willis Tower; Lizzie smashes her face into it. Part of that is CG, lit to match the plate, and then all the destruction.”

An interior view of the tower under attack was filmed on a sound stage in Atlanta with desks and office furniture. Behind that sees a CG Lizzie tear through. “The interior shots were actually pretty tricky,” notes Unterfranz. “It was a lot of destruction, and that smaller scale stuff like ceiling tiles, chairs, and pot plants, paper, and sparks – I always find the difficult stuff to really make sure you’ve got right is the stuff we see every day.

Weta Digital modelled the tower in CG based on reference, which then fed into the studio’s destruction sims. “Knowing that our modelling team was putting all the bells and whistles into the 3D version of the tower, we needed to plan for a procedural approach to handle all the different floors, sections, and materials within the tower,” says Nixon.

“Our destruction leads, Zeljko Barcan and Seb Schmidt, built workflows and tools around our in-house developed Houdini workflow called whRigid (Weta Houdini Rigid) to split assets by material types (steel, concrete, drywall, wood, glass, etc). It also allowed us to pre-fracture or bend and constrain those materials based on pre-approved material looks.This workflow meant we could examine how much data we were creating before starting to simulate, and whether or not adding or subtracting detail based on the shot requirements was necessary.”

“We would then package the newly created geometry into a renderable state with our in-house renderer Manuka,” adds Nixon, “and simulate the motion within Houdini DOPs, with all of the pre-determined constraints and physical settings those material types required in an optimized and logical workflow.”

After the main destruction simulations were completed, Weta Digital’s volumetric artists, led by Eddy Purnomo, built a framework using the studio’s Houdini results and proprietary volumetric simulation tool Synapse. “Starting from our Houdini results,” relates Nixon, “we would handle different emission criteria for our volumetric simulations, including rules such as impact force between objects, speed of objects at time of impact, surface area the of collision and material types, that were involved in the interaction. Using these rules, we could automatically generate secondary emission criteria for our volumetric simulations in order to make our dust behave correctly, as well as dynamically achieve the correct blend of colours. We also developed volumetric turbulence models and wind forces to match the pyroclastic look of the reference provided to us by the client which illustrated volumetric plumes within urban environments.”

Federal Plaza: making rubble

The Willis Tower’s destruction takes out four buildings and spills a heap of debris into Chicago’s Federal Plaza. This becomes the battlefield for the monsters, who had to interact with the rubble and debris pile.

“We spent a bit of time on the debris field, and I think that might have made people nervous a little bit that we were spending weeks building up this junk pile,” admits Unterfranz. “In reality, it’s not just the terrain that they’re on; it’s, they’re interacting with it. George pulls a crane out of it, and Lizzie’s stomping through it.”

“We knew that the Federal Plaza aftermath was going to be a fun challenge with the initial build of the environment itself and our creature’s interaction simulations,” states Nixon. “Brian Silva, one of our FX Leads in the Federal Plaza showdown, worked with our Layout team to build a workflow that allowed us to first simulate the placement of debris, and then ingest that geometry for simulating character interaction of the rubble. Because we built a workflow that lived within the same network of tools, we dealt with a lot less back-and-forth within the pipeline.”

The workflow involved building sheets of terrain made up of the debris, with the same pieces of debris dressed on top of those sheets, with some hero debris scattered throughout. The debris was also informed by what had been filmed on the Atlanta set, as Unterfranz explains. “Layout would go in and rough in just a sheet of geometry, based on the previs, but we took that a step further and integrated debris into that thing, and that was going to be just a solid piece. At one point, we did a CG photogrammetry pass of it and tried to break it down to one piece of geometry, and then we did some render optimisation testing, instancing the individual pieces versus using these larger sheets. We wound up having four unique bits of debris field.”

Initially, an approach Weta Digital had taken for the planet Ego on Guardians of the Galaxy Vol. 2, where the complex environment was made simpler for rendering purposes, was tried. Ultimately, the debris pieces were instanced and the combination of the multiple underlays allowed for a realistic interaction of the CG creatures amongst the rubble.

Simulating the aftermath of the tower fall was only half of the story, of course, since Weta Digital’s compositors also implemented smoke and dust passes, waves of falling debris and other volumetrics. “We had a brief from Colin Strause,” outlines Winquist, “saying that Jaron Presant, the cinematographer, wanted to play the beginning of this very much like some of the horrible reference that we’ve seen from immediately after 9/11 when it was just pea soup thick, but you could see there was a sun back there somewhere. We knew we wanted to play this almost straw colour of a warmth, and warm sun back there someplace coming through something that’s a mixture of dust and concrete. So it really was down to just art directing a lot of that on the comp side.”

Rampage by name, and by nature

For Weta Digital, Rampage was certainly a film that catered to the studio’s strengths: photoreal beasts and heavy destruction. But Winquist says the usual experience of doing that on a film was elevated – in an extremely positive way – by the outlandishness of the story. “The thing that was clear from the onset was that it was a movie that knew what it was,” the visual effects supervisor says. “It doesn’t take itself too seriously. I mean, my eyebrow went up a little bit like, ‘They’re making a movie of this video game?’ But the screenwriters came up with something pretty interesting. And then you throw Dwayne Johnson into the mix, who has a very particular kind of character that he plays and a very particular kind of movie that he’s in. It was a blast.”

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