  The numerical resolution efficiency of phase-field models is limited by grid
friction, grid anisotropy and pinning. The 1D sharp phase-field model
eliminates grid friction and pinning by a global restoration of Translational
Invariance (TI) in the discretized phase-field equation (Phys. Rev. Lett. 121,
025501, 2018). In 3D global TI restricts the beneficial modeling properties to
a finite number of fixed interface orientations. We propose an accurate scheme
to restore TI locally in the local interface normal direction. At
one-grid-point interface resolutions, the new model captures the formation of
isotropic seaweed structures without spurious dendritic selection by grid
anisotropy.
