The practicalities of limb removal. An excerpt from issue #46 of befores & afters magazine.
When Dek meets Thia, it quickly becomes apparent that the synth has been damaged and lost her legs when her Weyland-Yutani team had attempted to capture the Kalisk creature. During filming, production came up with several ways in which Fanning could be supported, either while sitting, appearing to be propped up on her torso or even being carried on Dek’s back.
Dumont studied a range of videos of people who do not have legs and can walk with their arms to help reference the kind of balancing required and look and feel for the Thia character. One outcome was to always remember that the character had to have at least one hand on the ground or touching something, for balance. “I wanted to make sure that we had enough supports for the character, to feel like she was always supported accurately,” details production visual effects supervisor Olivier Dumont. “So the idea was a bit of a tripod thing, with the spine as one point of contact. When she moves with her hands, she could put the spine down, otherwise it would be up all the time just moving with her arms. We had a lot of discussions with Elle about it and how she has to act.”
“We made the decision early on to have Elle really there,” remarks Siegel. “Schuster-Koloamatangi’s performance would be different otherwise, and the physicality and the relationship it built, having them physically close together was super important to Dan. It also supports the edit in a way that Dan could just be cutting material as if it was live-action because they were really there.”
For shots of Thia on the ground, a variety of camera tricks and rigging were utilized to help sell the fact that she had no legs, such as creating a hole in the ground for Fanning to sit in, and then VFX fixing the hole later. Things got more complicated for the times Thia was strapped to Dek’s back, sometimes even when he is running with her in rugged environments, as shot on location in New Zealand.
“We had to work out entire rigs with stunt coordinator Jacob Tomuri and the stunt team for that,” explains Dumont, noting that Tomuri produced a video suggesting different ways of being able to carry her without putting unnecessary weight on Dimitrius. “If Dek was running in a straight line, then wires and a harness would work. But if he had to curve around, then the line wouldn’t work because as soon as Dimitrius would go away from it, the whole weight would come away. So we came up with a rig that was like a wheelchair or rickshaw. Elle would be sitting on a wheelchair behind Dimitrius so he could really go wherever he wanted.”
“It was still very limited,” notes Dumont, in relation to the wheelchair rig. “Because of the nature of the rig, she couldn’t put her hands down really next to her hips, for instance. That’s why, as you can see, she’s always doing something with her arms. Elle Fanning came up with that. I thought it was great!”
For other complex shots, such as Thia going from a back-strapped position to on the ground, or vice versa, some very specific ways of filming were established. “At the end of the campfire scene, for instance,” shares Dumont, “when they leave in the morning, Dek grabs Thia and puts her on his back, and attaches her. That was all Elle. There was no rigging. She was just following what Schuster-Koloamatangi was doing and adding a little bit of movement to make it feel like she was being lifted up.”
On set, Fanning wore bluescreen-colored clothing for her legs and torso area, alongside some tracking markers, to make it plain where her real limbs needed to be removed. This was worked out with the costume department. “The costume designer Ngila Dickson and I talked about where we wanted the limit of her actual costume would be,” shares Dumont. “I knew I wouldn’t be able to be consistent in terms of length for what sticks out from her body to touch the ground. I wanted to make sure that we understood that the parts could move separately. We used tracking markers along that line. Elle was then wearing a blue leotard for the legs.”
Shooting clean plates was crucial for Thia shots. “When there was a lot of movement, we would shoot tiles, which made it easy to put a background back into the shot,” says Dumont. “The hardest part was when Thia was on Dek, because here she would be occluding his legs. That meant we had to go brute force and do CG legs. Also, when we shoot from the side, the arm or hand on the other side would have to be re-created because it would be hidden by the legs as it hung down. So, there were a lot of reconstructions of the plate.”
The damage to Thia causes parts of her synth innards to be poking out and flailing around. Dumont considered these insides to be a mix of sturdy parts—even a spine to lean on—and others that would move around. “You have those very synth-like tubes with balls on it and a little bit of light from them. There were also cables sticking out, and all that had to be sim’d. Fortunately, by the time she was discovered by Dek, the white blood was largely gone, so we didn’t need to do too much fluid simulation for that. For the spine itself, at first the vendors were going in a direction where it was very flexible, but I wanted to make sure that it was looking solid enough to be used as a support. So we just introduced it in some shots where she’d thrown up or seen rolling.”
“I think what made those Thia shots really successful was adding in a bunch of teeny little subtleties,” adds Siegel. “We did more than just erase the blue and paint in what’s behind it. I think the movement of her ‘mechanics’—which is what we came to call them—and the fact that they have this subtle movement up and down and back and forth to show that they were part of a larger whole and that they move in a familiar way as we imagine our own hips and our own spine moving. I think that does a lot to sell the effect.”
Just like Dek, several vendors combined to realize Thia shots, including Wētā FX, Trixter, Important Looking Pirates, Framestore and ILM. The Yard also contributed a specific moment of Thia attempting to use a ‘healing’ medical device to secure her legs back onto her body. “Dan really fell in love with that early on and it inspired another sequence in the film,” says Siegel. “It inspired the later scene where Tessa is being repaired by Weyland-Yutani.”
From Wētā FX’s point of view, the Thia leg shots involved a significant amount of prep work. “We obviously needed to take care of a lot of paint work there to get rid of the body parts that you wouldn’t want to see,” outlines Wētā FX’s Sheldon Stopsack. “At the same time, we went the full length of camera track and match move of every single piece that became relevant for us. It was always with the idea of preserving the practical legs wherever possible, and then adding the sliced parts to it and doing a very detailed camera track for those bits.”
In one particular moment, Thia’s detached legs are utilized to help take on a group of attacking synths. The film’s stunt team crafted stuntvis for the sequence. For filming, Fanning performed various elements, with stunt performer Rosalie Button taking on the action beats, this time wearing costumed legs, and a blue leotard from her waist up, with tracking marks around her waist. Wētā FX was responsible for the visual effects for this fight, also helping to motion capture a few extra moments for it.
“There’s that one shot,” recounts Rapley, “where the legs run up a guy and the synth accidentally takes his mate’s head clean off. There had to be some digital work there to make that all come together. I went down to the stage and we had a harness and we had a couple of stunt performers and we had a wall and we had them run up and we did a complete flip over, and then we put our leg puppet on that. That started actually looking pretty good and we’d then keyframe on top of that to get the posing just right.”
