  High-order bases provide major advantages over linear ones in terms of
efficiency, as they provide (for the same physical model) higher accuracy for
the same running time, and reliability, as they are less affected by locking
artifacts and mesh quality. Thus, we introduce a high-order finite element (FE)
formulation (high-order bases) for elastodynamic simulation on high-order
(curved) meshes with contact handling based on the recently proposed
Incremental Potential Contact (IPC) model.
  Our approach is based on the observation that each IPC optimization step used
to minimize the elasticity, contact, and friction potentials leads to linear
trajectories even in the presence of nonlinear meshes or nonlinear FE bases. It
is thus possible to retain the strong non-penetration guarantees and large time
steps of the original formulation while benefiting from the high-order bases
and high-order geometry. We accomplish this by mapping displacements and
resulting contact forces between a linear collision proxy and the underlying
high-order representation.
  We demonstrate the effectiveness of our approach in a selection of problems
from graphics, computational fabrication, and scientific computing.
