Shaping The Elements: Curvenet Animation Controls In Pixar’S Elemental

Shaping the Elements: Curvenet Animation Controls in Pixar's Elemental

Nguyen, Talbot, Sheffler, Hessler, Fleischer, de Goes

SIGGRAPH Talks (2023)



ABSTRACT We present a new shaping rig for authoring layers of animation control that facilitate surface editing in shot work. Our approach expands the curvenet rigging technology [de Goes et al. 2022] by introducing new tools that auto-generate a surface-aligned direct manipulator per curvenet knot. As a result, we obtain a mapping from animation controls into curvenet adjustments relative to the deforming surface with minimal setup. We showcase our curvenet shaping rig using results from Pixar’s feature film Elemental (2023). ACM Reference Format: Duc Nguyen, Jeremie Talbot, William Sheffler, Mark Hessler, Kurt Fleischer, and Fernando de Goes. 2023. Shaping the Elements: Curvenet Animation Controls in Pixar’s Elemental . In Special Interest Group on Computer Graphics and Interactive Techniques Conference Talks (SIGGRAPH ’23 Talks), August 06-10, 2023. ACM, New York, NY, USA, 2 pages. https://doi.org/10.1145/ 3587421.3595415 1 INTRODUCTION The characters of Pixar’s feature film Elemental (2023) are personifications of the classical elements of water, fire, and air. To Permission to make digital or hard copies of part or all of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. Copyrights for third-party components of this work must be honored. For all other uses, contact the owner/author(s). SIGGRAPH ’23 Talks, August 06-10, 2023, Los Angeles, CA, USA © 2023 Copyright held by the owner/author(s). ACM ISBN 979-8-4007-0143-6/23/08. https://doi.org/10.1145/3587421.3595415 capture the fluidity of these elements, our animation team envisioned early on production the need for shaping controls that refine the character articulation within the shot context. Unfortunately, existing techniques to create shot-based animation controls are limited to sculpting and transient rigs, which are often hand-crafted and intricate to setup. In particular, our animators sought a sparse representation that can express subtle shape adjustments, while being easily keyframed and constrained to the deforming surface. In this work, we present a new shaping rig that provides fine animation controls with minimal setup. Our approach builds on the curvenet rigging technology introduced by de Goes et al. [2022]. By exploiting curvenets, animators have access to modular curve controls expressing surface profiles and layered over the character articulation agnostic to the underlying rig or surface tessellation. Additionally, we devised a new deformer that auto-orients direct manipulators attached to curvenet knots, thus defining animation scopes for rotates, translates, and scales relative to the deforming surface free of any extra rigging setup. Equipped with these