Physics-based Character Skinning using Multi-Domain Subspace Deformations

How to read this

Category

Method: physics-based character skinning via multi-domain subspace (model reduction)

Contributions

• A domain-decomposition method simulating articulated deformable characters entirely in a subspace, supporting quasistatic and dynamic deformation with nonlinear kinematics and materials at interactive rates
• Bone-associated domains each with a local-frame deformation subspace from quasistatic poses and modal analysis, with reduced forces via cubature and penalty-based spring coupling to avoid locking and seams
• A Fast Sandwich Transform that evaluates inter-domain coupling between rotated domains without vertex-dependent runtime cost, reporting three-to-four orders of magnitude speedup over full-rank simulation

Context

Builds on physics-based anatomical character simulation (e.g. Teran et al.'s skeletal muscle work) and subspace/model-reduction deformation, partitioning the body per bone to keep reduced bases tractable.Builds on: Creating and Simulating Skeletal Muscle from the Visible Human Data Set

Correctness

Speedups are reported against full-rank unreduced simulation on quarter-million-element models; as a reduced-order method its accuracy depends on the quality of the per-domain subspaces and cubature, and penalty-based coupling trades exactness for stability, so a reader should weigh fidelity against the reported speed.

Clarity

Technical model-reduction paper; a first pass conveys the domain-decomposition strategy and payoff, but a second pass is needed for the subspace construction, cubature, and the Fast Sandwich Transform.

How to read it

First pass for the per-bone subspace decomposition and coupling idea; second/third pass on the Fast Sandwich Transform and cubature math if implementing or benchmarking reduced character simulation.