Probability distribution functions of the cosine of the angle between the reionisation patches and their corresponding filaments (as explained in Sect. 2.4) of the fiducial model (ζ = 30 and T_vir = 5 × 10⁴ K) with the different persistences used in DisPerSE, accumulating all patches of every run. The model with the 0.5-σ persistence is also represented (in grey) with a rotation of filaments in order for comparison with total randomness.