  We discuss the general formalism for the calculation in light-front quark
models of the fully unintegrated, off-diagonal quark-quark correlator of the
nucleon, parametrized in terms of generalized transverse momentum dependent
parton distributions (GTMDs). By taking specific limits or projections, these
GTMDs yield various transverse-momentum dependent and generalized parton
distributions, thus providing a unified framework to simultaneously model
different observables. The corresponding distributions in impact-parameter
space are the Wigner functions which provide multidimensional images of the
quark distributions in phase space. We present results within a light-front
constituent quark model, discussing some of the complementary aspects encoded
in the different distributions and the relation to the quark orbital angular
momentum of the proton.
