O III 5594 Å line, the C III 5697 Å line and the N IV 4059 Å line for the 3D O-star simulation, (a) using 65 snapshot-sphere models (the red lines show the result when all lines are averaged), (b) using mixed-sphere models (the red lines show the result when all lines are averaged), (c) showing averaged lines from both the snapshot-spheres (blue line) and mixed spheres (red line) and (d) showing averaged lines for the mixed-sphere models for both the ‘3D’ (unaltered) models and the 1D averaged, velocity-field-turned-off models.