Fast Complementary Dynamics via Skinning Eigenmodes

TL;DR

This paper introduces a novel reduced-space elasto-dynamic solver that leverages a skinning eigenmode-based deformation subspace, enabling efficient, rotation-equivariant secondary motion simulation in character animation.

Contribution

It presents a new skinning eigenmode-based subspace parameterization and a local-global solver for efficient, rotation-equivariant character animation simulation.

Findings

Captures rotational motion effectively.

Ensures rotation equivariance in simulations.

Provides a compact, mesh-decoupled simulation method.

Abstract

We propose a reduced-space elasto-dynamic solver that is well suited for augmenting rigged character animations with secondary motion. At the core of our method is a novel deformation subspace based on Linear Blend Skinning that overcomes many of the shortcomings prior subspace methods face. Our skinning subspace is parameterized entirely by a set of scalar weights, which we can obtain through a small, material-aware and rig-sensitive generalized eigenvalue problem. The resulting subspace can easily capture rotational motion and guarantees that the resulting simulation is rotation equivariant. We further propose a simple local-global solver for linear co-rotational elasticity and propose a clustering method to aggregate per-tetrahedra non-linear energetic quantities. The result is a compact simulation that is fully decoupled from the complexity of the mesh.