Technology of Animation
The Creature Assembly System
DreamWork's Animation newest film The Croods follows the world's first modern family as they embark on a journey of a lifetime when the cave that has always shielded them from danger is destroyed. Traveling across a spectacular landscape, the Croods discover an incredible new world filled with fantastic creatures as they learn that the one thing they need to survive is each other. In order to create the lush, vivid environment as the backdrop for the Croods' adventure, the filmmakers requested 35-40 unique creatures to be developed to populate the movie. This is an astonishing number for an animated feature film.
Before a 3D character model can be handed over to a team of animators, it must be bound to a system of joints and control handles known as a rig or "digital skeleton." This process is completed by artists known as Character Technical Directors (TDs), or Riggers. Like a real skeleton, a rig is made up of joints and bones, each of which act as a "handle" that animators can use to bend the character into a desired pose. Animators are then able to make the character models walk, run, jump, swing, etc. Traditionally the process of creating this "digital skeleton" and then programming it to move in distinct ways would take between three and six months for each character, and as such, the filmmakers' vision of a dozens of Croodaceous creatures populating their film would have been nearly impossible - those 35 creatures could have taken a minimum of nine years to create!
But when our filmmakers brought this challenge to the Character Technical Directors - essentially the creative engineers on our films - they found an innovative solution. To meet the rigging challenges of The Croods, the Character TD Department developed the Creature Assembly System, which provided a cost-effective and flexible solution for rigging a large number of unique and highly-stylized creatures. This system consisted of a collection of rigging "packages" and a tool to assemble them into a working rig.
Fundamental parts of creatures, such as limbs, spines, necks, wings and tails were identified. Motion systems for these parts were then built as standalone rigs called packages. The process of creating each new package involved: (1) the analysis of the required motion; (2) the construction of the motion and deformation systems; and (3) the declaration of the inputs to and the outputs from the encapsulated system.
The Character Creature Assemble Tool was developed to allow riggers to interactively specify which packages constituted a creature rig. The tool generated data format files, overlays and pages; effectively assembling a working rig.
Every creature in The Croods used the Creature Assemble System as part of their body rigging. Thanks to this approach, the production was able to rig a much larger number of unique creatures at low cost. Face rigging for creatures followed many of the same ideas. Ancillary rig components, like rabbit ears, were also rigged using this approach, further demonstrating its extensibility. Now, thanks to this approach, audiences across the country will soon have the pleasure of meeting the Mousephant, Crocopup, Macawnivore, Trip Gerbils, Turkeyfish, Turtle Dove and the Punch Monkey among others (see attached graphics).
Although tailored specifically to meet the needs of The Croods, the Creature Assemble System proved that a package-based approach to rigging characters would work in the studio's current pipeline. In addition, Next-Gen rigging is adopting this paradigm for all character rigs, including humans. This approach has allowed the rigging department to effectively develop a library of high-level, encapsulated components that is now shared across shows.