  In recent years, there has been a breakthrough in lattice calculations of
$x$-dependent partonic distributions. This encompasses also distributions
describing the 3D structure of the nucleon, such as generalized parton
distributions (GPDs). We report a new method of accessing GPDs in asymmetric
frames of reference, relying on a novel Lorentz-covariant parametrization of
the accessed off-forward matrix elements in boosted nucleon states. The
approach offers the possibility of computationally more efficient determination
of the full parameter dependence of GPDs and as such, it can contribute to
better understanding of nucleon's structure.
