The formation of a vein during cyclic shearing of a single copper crystal oriented for single slip can be followed in transmission Laue diffraction by analyzing the spatially resolved lattice rotation evolution. Because Laue transmission integrates the signal over the thickness of the sample, the structure of the vein in the beam direction is a priori believed to be inaccessible. Here we show that the vein geometry in the beam direction can be retrieved by comparing lattice curvature tensor components from crystal plasticity finite element simulations with those experimentally derived. Virtual sectional analysis facilitates the interpretation of the measured lattice curvatures of quasi-2D dislocation structures, allowing identifying a vein morphology that is slightly vertically and horizontally inclined in the through thickness direction. (C) 2017 The Authors. Published by Elsevier Ltd.