Key words

visual effects, VFX, Double Negative, BUF, MPC, The Moving Picture Company, Framestore, John Carter, Marsupilami, Titans, Harry Potter, Chabat 

Never before have VFX and animation been so close: a technological, artistic and even economic community. It's quite hard to say today whether Spielberg's Tintin is an animation feature or a live action film with embedded VFX. Ditto for Avatar. The borderlines are increasingly blurred and the artists are increasingly open.

The Titans of MPC

Gregory Fisher, in charge of animation for the London studio The Moving Picture Company (MPC) spoke of the various steps composing the seminal sequences of the Jonathan Liebesman feature film, Wrath of the Titans, released in March 2012. "Our main job at MPC consisted of creating and animating the film's mythical creatures as well as replacing the characters who are their victims", an equivalent of about 280 shots. Before expounding on this aspect of the production, the animation director conveyed a number of interesting figures about the backstage side of the production. As a matter of fact, of the 280 shots planned for the production, only 150 were fully completed. 87 were begun but then abandoned and 32 reached the animation phase before, in turn, being cut out in the final edit.

There were 190 MPC team people working on this film, of whom 18 for the animation department, 10 for asset management, 8 for environments, 15 for lighting, 18 for visual effects, 19 for match moving and rotoscoping (based in India) and 32 for compositing.

The first creature presented by Gregory Fisher is the renowned Chimera, a mythical animal with a lion's head, a goat's body and ending in a snake's head instead of a tail (as Homer described). "The first designing began in summer of 2010 and much debate arose concerning the beast's two heads: some were for an overlay, others were for parallel positioning. By going back to the script, we were able to highlight the technical and artistic challenges and, finally, to choose the second option… which had an impact on the overall anatomy." The movie's Chimera also has a pair of wings. The question of wing type (dragons, bats) led to more discussions, as did its capacity to fly, since this would have had an impact on the skeleton. Another stumbling block was the wing texture. Without or with hair, and if so, what type and what length? As Fisher stated: "For each body part we gathered a phenomenal number of reference points, and each point was discussed." So much so that the final concept was decided… by Framestore.

Once the design was green-lighted, MPC started the rigging (of the skeleton and the underlying musculature) using proprietary software that provided a good level of control over the so-called soft and flexible areas, quite useful in the case of this creature.

The fire spewed by the Chimera was also carefully plotted out: in the end it was decided that both heads would be used conjointly – one spraying out flammable fluid and the other igniting it – with the flame density tested by flame-thrower references. For the animation preproduction, MPC based its work on many stock shots of lions chasing down their prey: quick but muddled, resulting in uncontrolled skids. Postural tests were also done and "led not only to staging clues for the director, but also ended up helping the animators." For the attack scene on the village, in which the hero Perseus is able to defeat the Chimera, the teams first shot a live action version and then the layout experts integrated a low-def model of the Chimera, sometimes with actor Sam Worthington, also in low-def modeling, for shots where the two interact. In the final scene where Perseus strangles the Chimera with a heavy chain, the film team first shot the protagonist using props against a green screen, and then the artists designed an animated version of it to be able to integrate a CG-animated chain to lasso and strangle the beast.

Speaking about the second sequence shot, Gregory Fisher explained the work done on the Makhais, the two strange demons which have two legs but also two torsos, two heads and six arms. It took lengthy deliberation to determine the skeleton: "It was absolutely essential for the creature to be able to move freely, without impingement from normal skeletal constraints. So we began with a frame having "smashed" joints so that there would be no limits placed on it at all."

For MPC it was "no holds barred" in securing the skin references: real hospital cases of lesions and, more prosaically, a mechoui or spit roast for the team and also the pictures of burns. In order to animate the skin the studio applied a system of blend shapes where the muscles govern the epidermis. Some staff members even filmed themselves in similarly-framed shots so as to better define the animation and the physical traits of the demon.

Marsupilami by BUF

In 2004, Alain Chabat decided to explore the possibility of a film adaptation of the Marsupilami character, the hero of Franquin's comic series along with Spirou and Fantasio. And in 2008 Jamel Debbouze made several attempts to "embody" the animal at the BUF Compagnie studio, one of the director's historical partners, especially for his ad productions. Finally, the project definitively kicked-off in 2010, but without exact specifications concerning "which" Marsupilami would be chosen for the screen. "Work-wise, Alain Chabat is someone who's very meticulous" specified Olivier Cauwet, VFX supervisor at BUF, "but he's also someone who's very open and who expected us to make suggestions." So lots of roughs were requested from such artists as Hervé Barbereau, Fabien Ouvrard and Nathanaël Bronn: "Above all, we needed to confirm the proportions, given that when the shoot began we had no predefined design to work from." Once the 2D design was pre-approved, the BUF teams moved onto the CG work to build the rigging and the set-up, with leeway for subsequent modifications. As for many other studios, BUF's work is based on proprietary tools – in this case both for the shaders and for the hair formation.

Next, in order to prepare for interaction between the Marsupilami and the actors or the environments or both, a number of systems were used: the actors were entwined with several ropes to mimic when the animal's tail was to enwrap them, gray spheres were positioned to catch the main light and its intensity, and chrome-plated spheres were used to catch the environment from a camera point of view. All of this was filmed along the presumed path of the Marsupilami.

For the animation, the director was firm about honoring Franquin's work and style: "There was no question of making it into a cartoon", recalled Bastien Laurent, head of animation, "but rather for viewers to rediscover in the shots: the poses, the expressions and, more generally, the familiar pictures from the comic book." For the next step, the animators filmed gibbons and other lemurs before starting in on the nuts and bolts of animating the shots.

"As a matter of fact, to guide us, Alain hired on the talents of Pierre-Alain Block, aka Piano, a graphics expert from Chez Wam. For each shot he laid out a very simple 2D animatics which, when combined with the director's staging ideas and the comic book's posed pictures, provided a perfect idea of what to head for." Inversely, several sequences were entirely open to suggestions by the animators: "Here we had the possibility to provide four or five versions of a shot, and then it was Alain Chabat who chose the one which suited him best, without any preconceived ideas. This was sometimes a bit complex."

Animating the Marsupilami's tail also took a lot of work: "The tail's a proper character", as Bastien Laurent put it, "so either it follows the Marsupilami's movements, keeping to physical constraints, or else it functions entirely on its own. That's why for many shots we made 2D models and then we rotoscoped them once they were approved."

In total, 265 shots required work by BUF, of which 225 in CG animation, representing 14 minutes of screen time. 60 graphic artists, including 20 animators, worked on the film for 8 months.

The Tale of the Three Brothers by Framestore

In the last part of the Harry Potter and the Deathly Hallows saga, Hermione Granger tells the saga's founding story, about the three Peverell brothers (Antioche, Cadmus, Ignotus) in their confrontation with Death. Although this is an integral part of the feature film, this tale was crafted in animation and carefully entrusted to the teams of the London studio Framestore. Strangely enough, the project did not end up in the feature film department but rather in the advertising department, "since it had a production pipeline that was already more flexible for the film than that of the VFX department," as Dale Newton, head animator for the studio, explained in his opening lines.

As usual for such projects, the first step consisted in finding references to define the concepts of this integral short film: "With Ben Hibbon, the tale's director, we focused our research on shadow theater, since it's both highly sophisticated and so refined." Among other sources of inspiration, there was Lotte Reiniger, renowned German animator, Arthur Rackham, late 19^th century British artist and illustrator, and Edmund Dulac a native Frenchman and contemporary of Rackham, a great expert in Japanese prints as well as Persian miniatures. At the same time Framestore did shadowing tests with an ambient occlusion pass to produce the Death character, cloaked in veils and mist.

For the three brothers, it was decided to move away from the more traditional representation of Death "to move towards enhanced simplification of their designs."

Dale Newton also presented the technique used for the environments, called paper fog, which consists of velum cloth dipped in coffee to encompass matter for a fog-like effect. Alexis Liddell, a former student of Gobelins, l'école de l'image (France), was entrusted with designing the environments: the bridge, the tavern and also the room which are part of the sequence.

As decided, the three brothers were to have a relatively pure profile, so during the modeling phase "we experimented a lot with transparency, especially for their clothing, hinting at almost-geometrical bodies underneath," according to Dale Newton. Maya software was used for the modeling, while Zbrush and Photoshop served to create the shaders.

The animation proved to be just as complex to implement: "The first version was too explicit; we wanted something that flowed but with a fairytale or dreamlike tint. In addition, the director specified that he did not want a cut shot but a 2½ minute continuous take, something very difficult especially for the camera positioning."

The paper fog technique was quite important in the lighting phase. Using Nuke software, the Framestore team could intensify the atmosphere, creating something like a strongly-textured picture book that comes to life (further enhanced by the vellum effect). "The compositing was a very long process but we had enough time so were able to get it right. For example, on the veil enshrouding Death, we did plenty of cloth passes since this fabric seems to have a life of its own, giving it an animated esthetic that's like a piece of fine gauze floating through liquids. Finally it was in compositing where we were really able to obtain a finished rendering that we all liked."

John Carter of... Double Negative

John Carter of Mars is the adaptation of a series of science fiction novels, a cycle about Mars called The Books of Barsoom, written in the early 20^th century by Edgar Rice Burroughs (Tarzan's literary "dad"). Produced by Disney and directed by Andrew Stanton (Toy Story, Wall-E by Pixar), it tells the adventures of a former Confederate officer who is teleported to Mars (called Barsoom in the book) and who finds himself right in the middle of a civil war.

This feature film required no fewer than four studios to produce the 850 trick shots of this story, for which adaptations had already been attempted by Ray Harryhausen, John McTiernan and Jon Favreau. One of these studios, Double Negative, mobilized 150 artists on site in Singapore, and almost 1,000 at their Soho headquarters.

Double Negative worked on designing, modeling and animating the strange creatures inhabiting Barsoom, beginning with the Thoats, kind of beasts of burden and mounts encountered several times throughout the film. "At the beginning, we based our work on camels since we thought that they would pretty much represent the sluggishness and apparent apathy of these animals… with a certain alacrity in races when needed," stated Eamonn Butler, the studio's head animator. Motion capture tests were carried out but, given the complexity of the task, it was finally decided that actors should play on sets, rigged onto miniature 4-wheel drives, and that the creatures should be modeled and animated more simply in key-frame.

The Woola, another emblematic creature in the film, is a kind of family pet – and the faithful companion to John Carter, the human. The only difference: the Woola has a huge gaping mouth, six paws and moves incredibly fast. "Our first difficulty turned out to be these extra paws, since they necessarily had an impact on the rigging, on the one hand, and on movements, on the other. We also worked on gait cycles to better grasp these movements which needed to be fast but also needed to be discernable on screen. In the long run, since the wild chase scenes are part of a nocturnal sequence, we finally decided on a dust trail which would serve quite well in suggesting speed of displacement." Since it turned out to be very difficult to align canine references with what the director wanted, Eamonn Butler chose to cast… the animators: "One after the other we filmed them, and each of them was to show us what he or she thought the character's animation should be." The animators had to wear cardboard heads to imitate the Woola's and then move into casting mode so that they could all then decide which animator was either the best or at least the best embodiment of the beast! Last of all, the tongue – proportionately scaled to the hugeness of the jaws – was procedurally simulated with combined dynamics to perfect animation that included weight, inertia… and even flaccidness.

Nonetheless, the key characters of this strange world are – by far – the Tharks, green giants with four arms and two facial tusks who cross paths with John Carter. Not only was there the sheer design of these aliens to perfect, but a major challenge was to integrate them into a naturally-lit environment: this is because most of the film shoot took place in the Utah desert and the only source of light was the white desert sunlight which tended to blank out all details.

So Double Negative began its rigging work on a frame with four arms and all of the related joint constraints, before concentrating on the musculature and how it was going to impact skin movement. "At first we positioned a great many tendons so as to fine-tune push and pull variables, etc. But we also implemented a colored version of this muscle structure so that we could better understand the movements of each separate muscle and, if necessary, tweak one or the other to get us closer to realism, or to overplay the muscle power for staging purposes."

After the rigging, Dougle Negative started in on the facial animation with – as major stumbling block – those famous tusks on both sides of the Tharks' mouths. "And then the idea struck us, very simply" explains Eamonn Butler: "We'd position the facial capture cameras right where the tusks are, at 30° angles. In this way we'd have a capture as close as possible to the actors' faces and, in addition, they could play around with these camera/tusks, for example, to cast a dirty look above them. And so the cameras became an integral part of the capture." Double Negative added a full facial scan to this facial capture to obtain precise movements to be applied to a mesh.

To get optimum realism, Andrew Stanton also asked the actors – among them Willem Dafoe – to act out their roles in performance capture, in order to combine the already very physical body-performances of the actors with their facial expressions. Wearing stilts and gray jumpsuits, the camera team recorded the optical capture. Next, it was the animators' turn to act out the scenes, basing their movements on the previous recordings. As a result, whether the Tharks appear in outdoor sequences or indoors, they are perfectly integrated into the backgrounds, and the professionals' acting is preserved.

Drafted by Stéphane Malagnac, Prop'Ose, France
Conferences organized by CITIA
under the editorial direction of René Broca and Christian Jacquemart

Translated by Sheila Adrian

Contact: christellerony@citia.org