  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.
