The VLTI is the ideal instrument for measuring the distances of
nearby Cepheids with the Baade-Wesselink method, allowing an accurate
recalibration of the Cepheid Period-Luminosity relation. The high
accuracy required by such measurement, however, can only be reached
taking into account the effects of limb darkening, and its dependence
on the Cepheid pulsations. We present here our new method to compute
phase- and wavelength-dependent limb darkening profiles, based on
hydrodynamic simulation of Classical Cepheid atmospheres.