TRANSFORMING A MONSTER
MPC’S head of modelling Chris Uyede and lead rigging TD David Gower explain the making of a cinematic monster
MPC on how it created the treelike giant in A Monster Calls
We’ve had a number of fantastic beasts and creatures grace our screens in recent years, but few compare to the stunning tree-like giant of A Monster Calls. Like a gigantic Groot, MPC’S monster (voiced by Liam Neeson) is built from entwined wood and foliage, but the scale of the character put extra pressure on the animation and VFX team.
Led by MPC Montreal VFX supervisor, Ferran Domenech, the vendor provided 180 shots for the film, including emotional scenes with the monster as well as set extensions, to bring to life director Juan Antonio Bayona’s vision during the transformation sequence and the many close up shots of the monster.
“It was definitely a challenge,” states MPC’S lead rigging TD, David Gower. “The face rig was made up of hundreds of individual plates of wood and the trick was to get the right balance between wood that could bend but also maintained its stiffness and position relative to its neighbours.”
The team needed to research and develop new techniques to make the face flexible enough to perform a variety of humanistic expressions and lip-sync with actor Liam Neeson’s performance. At the same time, the structure of the model and rig needed to
the face rig was made up of hundreds of individual plates of wood David Gower, lead rigging TD, Motion Picture Company (MPC)
maintain the rigid appearance of wood – of many pieces of wooden branches and planks.
“We started from both the concept designs and the practical build,” says MPC’S head of modelling Chris Uyede. “While keeping the spirit of the design, we made a lot of modifications in order to support the articulation required to allow for an expressive performance. This involved a complete rework of his mouth, separating pieces and figuring out how they could bend or slide across each other as well as a lot of splitting in his brows.”
out of The woods
The end result was a face and body that was built like a giant jigsaw of hundreds of sliding pieces that retained their rigidity, avoiding a rubbery buckle or bend that was able to stretch or deform as the character was animated. Instead, the pieces were designed so they could slide alongside one another. David explains: “The rig was made up of three main layers. At its very core, it was a traditional biped rig driving a lowresolution version of the monster through skinning. This layer then drove each individual branch through the use of polygon strips laid out along the length of the branches. It was at this stage that we applied sliding and dynamics. The final render mesh was then wrapped on top.”
This technically complex approach kept the movement of the face grounded in reality and was inspired by real human anatomy. By following anatomical forms, the modellers and animators were able to represent muscle and bone with wood. “If you look at the construction of the branches you can read almost an ecorche sculpture,” identifies Chris. “obviously a lot of design licence was taken to make it a tree as opposed to a person, but the overall muscle flow is evident.”
MPC modelled and adjusted the monster’s facial anatomy from the original head scan supplied from production to work for the expressive dialogue performances needed. The CG modelling team modelled and textured the whole body as a mix of different types of virtual wood pieces intertwined with branches and vines that were then rigged to articulate and simulate a real musculature and nervous system. “The monster has an interior structure, complete
if you look at the Construction of the branches, you CAN read almost an ecorche sculpture Chris Uyede, head of modelling, Motion Picture Company (MPC)
with wooden heart, some larger driftwood type plates, branches growing out of his back and millions of polygons worth of small vines running over his entire surface,” says Chris. “The monster is built of 1,130 bespoke sculpted objects, not counting the procedurally generated vines.”
eye opener
When it came to the challenge of creating the monster, Chris points to the small vines that cover the character’s whole body. But that wasn’t the biggest challenge. There was almost a fur-based version. “We discarded a fur-based approach early on as we needed to be able to view from close up and required displacement and branching. This added a great deal of visual complexity to the character, as well as polys. rigging, caching and rendering them came at a big overhead.”
To really get under the monster’s skin and deliver a believable performance, the team focused on the eyes. While the monster model was constructed from entangled vines, branches and planks, the eyes remained warm and human-like.
Crucially for carrying the emotion of the performance, and seen in extreme close ups in many scenes throughout the film, the monster’s eyes had to be redesigned time and again to get them right. “The eyes in the practical build and early designs were not very human in appearance,” says Chris. “To support an emotive performance, the decision was made to push them closer to human eyes, Liam’s in particular.”
The monster’s eyes were redesigned to be closer to human eyes to achieve a deeper emotional connection with viewers, while maintaining the tree-like base quality which is central to the character’s look.
To achieve the warmer results of the eyes, the team used textures from light wooden surfaces on the sclera, then the art team turned to the moss that covers the monster’s body for the colour palette of the iris; the wet areas of the eyes were based on different types of tree sap.
final result
With the work complete, MPC’S animation team went beyond the emotional close up performances for the monster and created full keyframe animated shots of the body and the facial acting. To do this, the team used a wide selection of video references of Liam Neeson, as directed by Juan Antonio Bayona.
Although no motion capture data was used in the final shots, the witness and helmet camera video from these sessions provided perfect guidance for the animators as they worked with the audio.
This approach is best seen in the final emotional scenes as the monster helps the character of 12-year-old Conor face his nightmare, delivering subtle true to life acting and facial performance.