Ancestral Ties
Issue: Volume 40 Issue 1: (Jan/Feb 2017)

Ancestral Ties

Strong historical figures. Amazing period architecture. Exotic worlds. Intrigue. Murder. Devious plotting. Breathtaking parkour stunts. It’s all part of the Assassin’s Creed DNA.

For years, digital artists have created a video game franchise based on periods from past centuries, blending historical fact and fiction centered on the mysterious Knights Templar and the fictitious Assassins. Recently, this blended storytelling has migrated from a pure-CG delivery in the various iterations of the Ubisoft video game franchise to one that embraces physical sets, wirework for the complex stunts, and other practical effects in order to achieve the most realistic look possible in the film from 20th Century Fox.

“We were really determined to make an audience believe this world and these characters exist,” Justin Kurzel, director, has said.

Nevertheless, computer graphics played a vital role: The film contains more than 1,300 VFX shots that range in complexity. “While the intention was to shoot as much as possible in-camera, this really only gave us a framework to work with,” says Ged Wright, production VFX supervisor. “In the end, 90 percent of the shots have been manipulated in some way, from adjusting the camera, timings, lighting, and performance, to fully CG shots with crowds, effects animation, CG environments, and digital doubles.”

Destiny

The first Assassin’s Creed game was introduced a decade ago, followed by over a dozen more from eras including the Renaissance, French Revolution, and more. The central plot focuses on the ages-old struggle of two ancient secret societies: the Assassins, who fight for peace and free will, and the Templars, who also desire peace albeit through control. The games have both a historical and present-day element, whereby a modern-day descendant from a prominent line of Assassins is forced by a corporate front for the present-day Templars (Abstergo Industries) to experience ancestral memories via a device called the Animus, in hopes that he can lead them to ancient artifacts used to control minds. The hero begins working with modern-day Assassins in the games, using their Animus to continue experiencing past memories, with the goal of recovering the so-called Pieces of Eden artifacts, including the Apple of Eden, which contains the genetic code for free will, before the Templars do. Yet, some of the memories take a more permanent hold on the hero, both physically and psychologically, as the past and present “bleed” together.

The Assassin’s Creed film continues the main premise, introducing us to a new hero, Callum Lynch (Michael Fassbender), who is forced to explore the memories of his ancestor Aguilar, an Assassin from 500 years in the past during the Spanish Acquisition. “There were certain beats, such as the assassinations, that were heavily influenced by the games,” says Wright.

As in the games, the film features epic period vistas and action, transporting viewers to 15th century Spain, where Cal learns the knowledge and skills that enable him to take on the Templars in the present day.

Filming occurred in Malta, the UK, and Spain. “Justin [Kurzel] had a strong desire for things to be based in reality, and that, coupled with the live-action photography, gave the film a certain look,” says Wright. “So, aside from a few stylized flying shots, most of the work was bedded in reality.”

Nevertheless, digital effects were required to tell this fictional history lesson. The main CG work was used for scenes in the present-day Animus chamber and 15th century Spain, which the artists tried to make as immersive and tangible as possible in keeping with the games.

Double Negative was responsible for 457 shots, including the Animus chamber, which comprises the mechanical arm, significant set extensions, and the so-called Bleeding Effect, whereby the genetic memories of an ancestor begin to blend with a person’s own, real-time memory. The crew also handled the second and third regressions, which account for Cal’s trips to the past, including the complex rooftop chase in the second regression. The facility also took on the sweeping eagle vision shots, which are homage to the game, with the camera following the eagle through different environments and locations.

Meanwhile, Cinesite handled 209 shots across its Montreal, London, and Vancouver (partner Image Engine) studios. Cinesite Montreal was responsible for the first-regression wild wagon chase that ends with a “cliff-hanger,” the exciting finale in London, and the Apple of Eden shots in the Granada attack. Cinesite London focused on the Animus set extensions shots during the escape of the Assassins from Abstergo Industries, and enhanced the fight by adding CG weapons and re-positioning and re-speeding actors in the scene. The group also handled exterior greenscreen shots in which they added the city of Madrid.

Cinesite’s Vancouver partner, Image Engine, was charged with the action shots in the escape from Abstergo. This included the creation of CG weapons, such as knives, crossbow bolts, and arrows; face replacements; and enhancing the fight with effects.

One of Us took on a range of design and invisible work across the film. And, an in-house team and a number of other vendors picked up additional work as needed.

Dneg: Eagle Vision

Eagles play an important role to the Assassin Brotherhood. The birds swarm around high viewpoint structures that the Assassins use to navigate their surroundings and perform their signature Leaps of Faith from. In fact, Assassins dubbed the sixth sense that belonged to some of their members “Eagle Vision.”

At Dneg, Mattias Engstrom and Sebastian Becker led a team that created the CG eagle, whose look was based on an actual Iberian eagle, Princess, which was photographed in controlled lighting scenarios to used as reference. The bird was also digitally scanned by Propshop Digital using Agisoft’s PhotoScan, and the data used as the basis for the head and claws of the model, with the wings created based on anatomy diagrams. The feather system for the model was generated in Side Effects’ Houdini.

“We had more accurate control animating the feathers in animation and then using effects simulations to solve for geometry penetrations, than driving this as a simulation,” says Graham Page, Dneg’s visual effects supervisor on the film. “This meant a far greater degree of control and a quicker turnaround.”

To animate the eagle, the group again used real-world reference as a guide, often viewing those alongside the animation for accuracy. Most helpful, though, was the close-up reference footage of Princess in flight, shot in a wind tunnel. “That turned out to be the most useful for look development and reference for the motion of small tufts of feathers rather than the overall action, as [the bird] was too constricted in the studio space to act naturally, as if it was gliding out in the open sky,” Page explains.

Assassin's Creed
ARTISTS ADDED SET EXTENSIONS AND FULL-CG BACKGROUNDS TO SCENES, HERE RE-CREATING 15TH CENTURY SPAIN.

While the eagle appears in just a handful of shots, these include some of the longest, most complex in the film. “We had to build a complete CG version of ancient Granada that pretty much appears in only two of these flyover shots,” says Page. “So we were very much focused on these shots from day one.”

Moreover, the relation between the matchmoving, camera animation, and character animation were particularly tricky given the vast scale of the shots, with everything appearing in the far background except the eagle, which was close up. So, any small movements in the camera that were not apparent on the background would become massive jolts in the eagle, Page points out.

Cinesite: Wagon Chase

VFX also played a big role for the Wagon Chase sequence in the desert that ends with the wagon launching over a cliff. In the scene, Cal and Maria, an Assassin and his companion in the past timeline, are deployed to rescue the young prince Ahmed, kidnapped by the Templars to coerce Ahmed’s father to surrender the Apple. Maria hijacks a wagon with the imprisoned boy caged in the back. Templars are in pursuit, while Cal on horseback (as his ancestor Aguilar) tries to rescue the boy before the runaway prison wagon tumbles over the cliff.

“There’s quite a bit of CG,” says Christian Irles, Cinesite’s VFX supervisor on the film. “The wagon tumbling is CG, and so are its horses once they start collapsing to the ground. The cliff was modeled and textured in order to enhance principal photography, but also to achieve full-CG shots. We created a digi-double for Ahmed and used Dneg’s digi-Aguilar. There are also CG weapons and many, many layers of effects (dust and debris) throughout the sequence. Lastly, roto-animation models of the actors were used in shots with multiple plates to make sure their scale was correct.”

Assassin's Creed
DNEG CREATED THE EAGLE AND ANCIENT GRANADA IN THE BACKGROUND.

The sequence contains four main beats. “We tried to give a physical and photographic framework on which to base things, to lend the shots a more tangible reality,” says Wright.

As discussed earlier, parkour is a fundamental element to the fighting style in Assassin’s Creed gameplay and, now, the film. During the chase, Cinesite facilitated the parkour as Maria jumps from the front of the wagon to the back to fight a Templar, by pushing herself off a rock wall in a 360-degree slip. These shots consisted of background plates shot in Spain with the live-action wagon and rock wall, as well as greenscreen plates of Maria on wires doing her jump.

Assassin's Creed
THE WAGON CHASE HAS A MIX OF PHOTOGRAPHY AND CGI, INCLUDING ANIMATION OF THE WAGON BREAKING APART.

During the chase, Aguilar jumps from his horse onto the back of the wagon. For this, multiple plates were filmed for each shot. “We had to cheat the speed at which the horse was running; otherwise, it always felt as if Aguilar was jumping forward faster than the wagon itself,” explains Irles.

The actual wagon flip was by far the most complex beat of the sequence. “Unfortunately, the practical war wagon did not flip the way Kurzel wanted,” says Irles. Instead, it was done in CG.

After the 3D wagon animation was approved, the artists proceeded to the simulation work, to break the wagon apart as it tumbled to the ground. As the shots progressed, the artists also replaced the practical wagon horses with CGI. Because the horses had been filmed in a separate pass, they never reacted to the impact of the wagon. So, in the CG replacement, the horses were hand animated, and additional VFX elements were created. And, the Templar enforcer Ojeda and Assassin Aguilar are practical in some shots and full CG in others.

In the fourth beat, a practical wagon was pulled off an edge of land, though the artists digitally enhanced the environment to make the void feel much deeper. Cinesite then created a CG cliff using The Foundry’s Mari and Autodesk’s Mudbox and Maya. “It had to feel deep enough so that a person would not survive the fall,” says Irles.

Digital versions of Ahmed, Aguilar (made by Dneg but modified for Cinesite’s pipeline), and the prison wagon were also required for this sequence.

Other software used by the Cinesite artists for the sequence include Adobe’s Photoshop, Autodesk’s (Solid Angle’s) Arnold, Chaos Group’s V-Ray, Houdini, and The Foundry’s Nuke. Simulations – from dust and debris to the wagon disintegration – were accomplished in Maya and Houdini.

Cinesite and Dneg: Environments

Cinesite also contributed environmental work to the film. In the London finale, the team rebuilt the back of the theater (behind Alan Rikkin, the CEO of Abstergo) for shots inside the Freemason’s Hall. This was done in 2.5D using photographs provided by production. For the larger exterior shot flying above London, the artists re-created the city digitally.

Cinesite also constructed the outside shots of the Abstergo building in 3D. “They were quite tricky, as there were no background plates for them,” says Irles. “We had to build them from scratch using still-frame photography.” The immense compound was lit and rendered and then enhanced with digital matte paintings. Numerous layers of 2D smoke at varying depths helped create the final look.

Assassin's Creed
DNEG BUILT THE CG ANIMUS.

Meanwhile, the city of Madrid shown in the background of the sequence was achieved in 2.5D using photographs provided by production that were projected onto simple geometry – 2.5D digital matte paintings, essentially. CG cars helped give the city some life, and in two specific shots, trees and a cemetery were incorporated.

Assassin's Creed
CINESITE ARTISTS BUILT THE OUTSIDE VIEW OF ABSTERGO INDUSTRIES USING COMPUTER GRAPHICS.

One of the more iconic scenes from the game lore occurs a dynamic rooftop chase in ancient Spain, culminating in the signature Leap of Faith. Real actors did most of the action for the sequence – including the parkour and the amazing 125-foot free fall. The environment, however, was far less so.

Most of the shots had some type of unique design requirement, handled by the team at Dneg. “We had a lot of work to do laying out the shots and building the elements, not to mention the time spent adding the necessary detail, since many of the environments are also seen incredibly close up with shifting camera moves,” explains Page.

To build 15th century Seville, the artists used mainly Maya and Pixologic’s ZBrush, along with Houdini for the effects work. Isotropix’s Clarisse was used for lighting and rendering, and Nuke for compositing. According to Page, most of the shots were almost fully digital, apart from the characters, though the artists based their work on photographic reality, to help ground the sequence. For instance, in the buttress run section, which happens after the jump onto the tiled roof, only the characters are real. The team used photography of a dressed location in Malta that they re-projected as the basis for the backgrounds, and then combined it with fully-CG assets and some matte paintings.

The artists further used a good deal of reference photography from across Spain, such as Albarracin, which boasts red tiled roofs and medieval churches.

“The details helped us create an authentic look for the city,” says Page.

The hero reveal of the Seville Cathedral at the end of the sequence is based on footage of the actual Cathedral, and the layout of the city is in part based on the real city, though with the modern buildings replaced. However, with the surrounding scaffolding and markets within the scene, this structure became one of the more complex to build.

Dneg: Animus

Central to the story line is the Animus, a device used to take a person out of real life and into virtual reality, where the lives of their ancestors can be relived. In the games, this was a lounge chair with a VR headset, but in the movie, it takes on a whole new design: a mechanical arm.

“It was very much the vision of Justin [Kurzel], who wanted to steer towards a much more visceral, physical representation for the Animus, rather than having a character in a chair,” says Page.

The new look was designed by a team of artists on the production side and at Dneg led by the film’s VFX art director, Virginie Bourdin. A full-scale practical version was constructed, as well as a digital model that was created in Maya and ZBrush, and rendered in Pixar’s PRMan and The Foundry’s Katana.

And, there was always a performance by Fassbender upon which the animation was based. “For the Animus shots, we generally body-tracked Michael and then animated around the performance to make it feel like the arm was supporting and driving Cal, not the other way around,” says Page.

Blood Line

The Assassin’s Creed property was born from computer graphics, with CGI at the heart of its DNA. But, in a universe where game-to-film titles rely heavily on the property’s digital roots, the director of this film opted for an alternative path.

Nevertheless, 2.5D and 3D elements still course through the film’s blood, adhering to a legacy appreciated by die-hard Assassin’s Creed fans as well as those introduced to this world for the first time.

Karen Moltenbrey is the chief editor of Computer Graphics World.