  We study the sample paths properties of Operator scaling Gaussian random
fields. Such fields are anisotropic generalizations of anisotropic self-similar
random fields as anisotropic Fractional Brownian Motion. Some characteristic
properties of the anisotropy are revealed by the regularity of the sample
paths. The sharpest way of measuring smoothness is related to these
anisotropies and thus to the geometry of these fields.
