Making Souls: Methods and a Pipeline for Volumetric Characters

ABSTRACT The soul characters in Disney/Pixar’s Soul have a stylized appearance that sets them into a unique world, which introduced many new challenges. Everyone from the art department and character modelers and shaders to the technical directors and developers in the effects, lighting, and software groups collaborated to bring this new visual style to screen. The soul world is abstract and ethereal; this needed to be balanced with visual clarity and design appeal. As our character rigging and animation tools use rigged surfaces, a key challenge was presenting a new representation derived from this data that meets our visual goals. To achieve softness of volumetric form and dynamically changing linework, we built a system to procedurally generate this data in Houdini. Significant numerical computation was required to create this data at the fidelity required. We developed an automated system for managing this computation in a configurable way, while keeping data for downstream renders in sync with changes to character performances.