How Nolan Turned Homer's Cyclops, Giants and Sea Monsters Into Practical Effects Instead of CGI

When Christopher Nolan announced he was adapting the Odyssey, one question stuck with me: how was he actually going to pull off all the effects? Homer's nearly 3,000 year old epic is full of storms, mythical creatures, gods, monsters and a giant one eyed cyclops, exactly the kind of story most modern filmmakers would hand straight to a CGI team.

The problem is Nolan has spent his career doing the opposite, insisting on shooting as much as possible for real rather than leaving everything to a visual effects department. He flipped an actual semi truck for The Dark Knight and crashed a real 747 for Tenet, building his identity on an almost obsessive refusal to default to CGI. So was the Odyssey finally going to force him to give in, or was he about to push practical filmmaking even further than ever before? Here is how the effects actually came together.

The Cyclops Was Built From a Puppet, an Actor and a Lesson Borrowed From Guillermo del Toro

Of all the creatures in the Odyssey, the Cyclops probably presented the most obvious problem. He is an enormous one eyed giant who has to physically interact with Odysseus and his men, and the easiest solution would have been to put Matt Damon in front of a green screen and add the creature later. Instead Nolan wanted the actors, and the audience, to actually feel like they were trapped inside a cave with something gigantic and horrifying. To him it presented the same challenge as the Batmobile in Batman Begins, how do you take something fantastical and make people believe in it.

This is where Nolan borrowed a lesson from his friend Guillermo del Toro, who has spent his career making monsters feel like living creatures. Nolan said the biggest thing he learned from him was that "a monster is not a monster," and that you have to approach them the same way you approach any other character. That gives the Cyclops real weight, so it feels like something that already existed before these men wandered into its cave, to the point that you feel bad for it once they start attacking it. Visually, Nolan took inspiration from Francisco Goya's painting Saturn Devouring His Son, which they kept on the wall during development and used as a reference.

To actually bring the creature to life, Nolan turned to Bill Irwin, an actor, clown and mime he had worked with on Interstellar, where Irwin helped bring the robot TARS to life. Rather than one technique, the finished Cyclops was built from several practical elements. Irwin was filmed separately in full body makeup from a deliberately low angle, exaggerating his proportions and helping sell the illusion that a normal sized human was a towering giant. Then, when Damon and the other actors shot the cave sequence, Irwin was physically there providing the Cyclops's voice and vocalizations in real time.

Alongside him was an enormous 60 foot puppet version of the creature, giving the actors something tangible to interact with and a physical reference point so their eyelines would actually match the giant. Those elements, the performance, the puppet and the live action footage, were then composited together with some minimal CGI to smooth out the seams and blend everything into one convincing creature.

Forced Perspective Turned Real Height Differences Into the Film's Towering Giants

While the Cyclops required an elaborate combination of puppetry, performance and compositing, Nolan used a much simpler trick to create the film's giants, forced perspective. Rather than digitally enlarging performers, he manipulated the size relationship between actors inside the frame, using 7 foot tall stunt performers to play the giants opposite body doubles for the Greeks who stood under 5 feet tall. Matt Damon's double for these shots was a female stunt performer named Devyn Dalton, who was just 4 foot 6. Interestingly, that is actually Dalton, not Damon, seen from behind on one of the film's posters, because the image comes from one of these forced perspective setups.

Forced perspective is one of the oldest tricks in filmmaking. By controlling where performers are positioned relative to the camera, you can make one person appear significantly larger than another even though both are standing on the same set. The Lord of the Rings famously used the same basic technique to make Gandalf tower over the Hobbits, with Ian McKellen and the Hobbit actors often not actually standing beside each other at all, one positioned closer to the camera and the other further away, with specifically designed sets and camera angles making them appear to occupy the same space.

Nolan combined that basic principle with extreme real world height differences, so instead of asking the camera to do all the work, the production started with performers who were already dramatically different in size and then exaggerated that difference through perspective. A 7 foot stunt performer standing against a 4 foot 6 double already looks enormous, and once you manipulate their distance from the lens and compose the shot correctly, that difference becomes even more extreme.

Circe's Transformation of Odysseus's Men Into Pigs Used No CGI at All

Perhaps the most impressive practical effect in the entire film comes when Circe transforms Odysseus's men into pigs. In Homer's original poem Circe simply uses a wand, but Nolan turned the moment into something much more physical, with Samantha Morton's Circe literally using her hands to reshape the men into animals. Despite how impossible the sequence looks, no CGI was used in it whatsoever. Instead Nolan relied on a combination of animatronics, specially constructed prosthetic pieces and carefully chosen camera angles.

According to Tom Holland, the heads being manipulated by Circe were animatronic, meaning when Morton physically reshapes them on screen she is actually interacting with a practical effect rather than pretending to touch something added later with CGI. The whole sequence was deliberately built as a throwback to the golden age of practical creature effects, with Nolan citing The Thing and An American Werewolf in London as reference points, wanting to return to the tactile transformation effects that defined horror films in the late 1980s.

What makes the effect even more convincing is that practically everything surrounding it was real too. Circe's house was an enormous physical set built in Scotland, and it was apparently so convincing that when the actress playing Circe first arrived on set she assumed the production had simply found an existing building to shoot in. Once again, Nolan's approach was not to shoot actors against green screens and add CGI afterward. He built the environment, created the creature physically and used old filmmaking tricks to convince you that you were watching actual magic happen in front of the camera.

Scylla Was Mostly Digital, But the Stunts Around It Were Not

Nolan was not completely opposed to creating some of Homer's monsters digitally. The best example is Scylla, the six headed creature that attacks Odysseus's ship as it passes through the narrow strait opposite Charybdis. Unlike the Cyclops, Scylla was predominantly a digital creation, but Nolan still wanted as much of the action around it to happen for real. In the film each of Scylla's six heads swoops down and snatches one of Odysseus's men from the ship.

To give the digital creature something real to interact with, supervising stunt coordinator George Cottle rigged six separate professional ratchet systems directly onto the actual boat, used to physically lift the stunt performers off the deck during the attack. According to Matt Damon, Cottle rigged and shot the entire sequence after lunch, completing all six lifts in a single afternoon. That meant the visual effects team did not have to digitally animate the men being picked up from scratch, since the performers actually left the deck, their bodies reacted naturally to being lifted, and everyone else on the ship was responding to something physically happening in front of them.

Scylla could then be digitally added around that real stunt photography, essentially turning the practical action into the foundation for the finished visual effect. It is another example of Nolan using CGI less as a replacement for what can be photographed and more as the final piece needed to create something that obviously cannot exist in real life.

Charybdis's Whirlpool Started With Jet Skis Doing Real Donuts in the Water

Nolan used a similar approach for Charybdis, the giant whirlpool on the opposite side of the strait. Rather than generate the entire thing with CGI, he had jet skis repeatedly circle through the water beside the ship, creating a real vortex and giving the visual effects team the natural movement of the ocean as reference material. That practical disturbance was then replaced and expanded digitally into the enormous whirlpool seen in the finished film.

So, somewhat ironically, one of the film's most CGI heavy creatures still involved real boats, real ocean, real stunt performers being physically lifted off the deck, and jet skis doing donuts in the water. The monster itself may have been digital, but almost everything it was interacting with was not.

Shooting Entirely on IMAX Film Meant Solving a Noise Problem With a Soundproof Box, and an Eyeline Problem With Mirrors

Perhaps the biggest technical achievement of the Odyssey has nothing to do with its monsters. It was the first feature film ever shot entirely on IMAX film. Nolan had been gradually increasing his use of the format since The Dark Knight, but there was always one major obstacle, IMAX cameras are extremely loud. The film running through the camera creates so much mechanical noise that while it works for action sequences, which can have sound redone afterward, it has historically been a nightmare for quiet dialogue scenes where you need to actually record what the actors are saying.

So Nolan asked IMAX to develop a specialized soundproof housing for the camera, known as a blimp, essentially placing the entire camera inside a giant insulated box that muffled its mechanical noise just enough to record usable dialogue. But solving one problem created another. The camera was now so large that it could get in the way of the actors. Normally, if two actors are performing face to face, the camera can sit between them while they look past it directly at one another, but once you surround an already massive IMAX camera with an enormous soundproof box, the actors' eyelines become so far apart they can no longer see each other.

Nolan and his team came up with an almost hilariously low tech solution for one of the most advanced cameras in the world, mirrors. The crew positioned mirrors around the camera so that an actor standing beside the rig could look into one and see the other performer reflected back at them, keeping their eyeline close to the lens while still effectively making eye contact and reacting to the other actor in real time.

CGI Was Never the Default, It Was the Last Piece Added

For all the talk about Nolan's hatred of CGI, the Odyssey proves he is not actually opposed to digital effects. The difference is that he almost never seems to begin with the computer, he begins by asking how much of the effect can actually exist in front of the camera first. He did not make one of the most fantastical stories ever written by pretending CGI does not exist, he simply treated it as one tool among many rather than the default solution to every problem. Sometimes the answer was an animatronic, sometimes forced perspective, sometimes a digital monster, and sometimes, for an intimate conversation shot on the most advanced IMAX cameras ever built, the solution was literally just a couple of mirrors.

Which of these solutions do you find the most convincing, the animatronic Cyclops built from a puppet and a performer, the forced perspective giants, or the mirrors that saved eye contact on an IMAX shoot?