Methods of controllably creating three-dimensional (3D) combined-flow-interface patterns in multi-lane fluidic devices, and systems, apparatuses and software therefor. In one example, the 3D-pattern is created and varied as a function of one or more of the geometry of the inlets to a main fluidic channel in which the 3D-pattern is formed, the Reynolds number of the flows, the dimensions of the main fluidic channel and the inlets, and the spacing of adjacent inlets. In one embodiment particularly disclosed, differing 3D combined-flow-interface patterns are created using a three-lane fluidic device having a fixed inlet geometry. In another embodiment particularly disclosed, differing 3D combined-flow-interface patterns are created using a five-lane fluidic device having a fixed inlet geometry that can be used to effectively mimic variable inlet geometries.