  We investigate topography-driven generation of defects in liquid crystals
films coating frozen surfaces of spatially varying Gaussian curvature whose
topology does not automatically require defects in the ground state. We study
in particular disclination-unbinding transitions with increasing aspect ratio
for a surface shaped as a Gaussian bump with an hexatic phase draped over it.
The instability of a smooth ground state texture to the generation of a single
defect is also discussed. Free boundary conditions for a single bump are
considered as well as periodic arrays of bumps. Finally, we argue that defects
on a bump encircled by an aligning wall undergo sharp deconfinement transitions
as the aspect ratio of the surface is lowered.
