Comparison of eight radial disk height profiles on different diffusion timescales. Depicted is the height vertically above the midplane where the optical depth measured vertically toward the midplane from the box boundary reaches unity. The two magenta lines are cases with no dust diffusion (i.e., τ_diff = 0) for the old (solid lines) and new (dashed lines) versions of f_d2g as described in Sect. 2.1. The six other cases cover the range of diffusion times from 10 s to 10⁶ s. The small blue bar to the left represents one diffusion length in the vertical direction for τ_diff = 10⁵ s. It is significantly smaller than the change in shape of the corresponding blue profile.