Snapshots showing the evolution of three fiducial clouds computed at multiple time steps. Each column corresponds to a specific run (top: ECF1, middle: ECF2, bottom: ECF3) and rows give different epochs in each of them. The colour map gives the z integrated column density of the gas in M_⊙ pc⁻², while red circles correspond to sink positions and stars are coloured using realistic black body temperature extrapolated from a luminosity-mass relation. ECF1 presents a protostellar cluster under the influence of Η II regions distributed in various parts of the molecular cloud; for instance, Aquila. ECF2 presents a more centrally concentrated protostellar cluster, which develops a cluster of Η II regions, such as the region W43. ECF3 is more difficult to link with an existing star-forming region. As all the gas has been removed very rapidly, the resulting group of stars looks like a more evolved association or cluster such as NGC 6611.