  We show that surface interactions can vectorially structure the
three-dimensional polariza-tion field of a ferroelectric fluid. The contact
between a ferroelectric nematic liquid crystal and a surface with in-plane
polarity generates a preferred in-plane orientation of the polarization field
at that interface. This is a route to the formation of fluid or glassy
monodomains of high polarization without the need for electric field poling.
For example, unidirectional buffing of polyimide films on planar surfaces to
give quadrupolar in-plane anisotropy also induces mac-roscopic in-plane polar
order at the surfaces, enabling the formation of a variety of azimuthal polar
director structures in the cell interior, including uniform and twisted states.
In a {\pi}-twist cell, obtained with antiparallel, unidirectional buffing on
opposing surfaces, we demonstrate three distinct modes of ferroelectric nematic
electro-optic response: intrinsic, viscosity-limited, field-induced molecular
reorientation; field-induced motion of domain walls separating twist-ed states
of opposite chirality; and propagation of polarization reorientation solitons
from the cell plates to the cell center upon field reversal. Chirally doped
ferroelectric nematics in anti-parallel-rubbed cells produce Grandjean textures
of helical twist that can be unwound via field-induced polar surface
reorientation transitions. Fields required are in the 3 V/mm range, indicating
an in-plane polar anchoring energy of wP ~ 3x10-3 J/m2.
