“Metaball Madness: Look Development For A Shapeshifting, Implicit Surface Character On Pixar’s Elio” by Luo, Crow, Goes and Scheepers
Conference:
Type(s):
Title:
- Metaball Madness: Look Development For A Shapeshifting, Implicit Surface Character On Pixar’s Elio
Session/Category Title:
- Animating and Rendering Ooze
Presenter(s)/Author(s):
Moderator(s):
Abstract:
How do you shade a shapeshifting character created as an implicit surface? Elio’s OOOOO is Pixar’s first character whose body is made and rigged entirely as a controllable series of metaball-like signed distance functions, rendered for interaction with a GLSL shader [Lykkegaard et al. 2025] in our animation software, Presto. Although this novel approach facilitates incredible animation and movement, it eliminates the standard procedure of providing a stable mesh for shading, rendering, and deformation purposes. In visual design, OOOOO is a liquid supercomputer – one main body with accompanying blobs, all capable of separating and merging at any time, filled with a “nest” of separately created, moving circuit geometry, concentrated at the core. This talk will consider the accompanying set of challenges these factors created for look development past the model/rig stage. We will go through the tasks of creating a per-frame renderable mesh for OOOOO’s body using GLSL-to-VEX conversion and sparse volumes in Houdini, creating animated circuitry that correctly orients and appealingly deforms without simulation nor a traditional rig/consistent mesh, and creating primvars per frame using split meshing and volume operations in order to meet artistic direction. Additionally, we will discuss our overall goals and other considerations about efficiency, philosophy regarding animation and use of the rig, collaboration across departments, and how this one-of-a-kind character would really fit within our traditional pipeline.
References:
[1] Fernando de Goes and Alonso Martinez. 2019. Mesh wrap based on affine-invariant coordinates. In ACM SIGGRAPH 2019 Talks(SIGGRAPH ’19). Association for Computing Machinery, Article 4, 2 pages.
[2] Anna-Christine Lykkegaard, Andrew Butts, and Julian Teo. 2025. Metaball Madness – The Rigging Of An Implicit Surface Character. In under review.
