2D histogram representing the logarithm of the ratio of the number of patches to the total number of patches of the simulation in bins of triaxiality parameter and cosine of the angle between reionisation patches and filaments for the fiducial model (with ζ = 30 and log₁₀(T_vir) = 4.69897). The white full lines are the isocontours of the histogram. The coloured cells of this histogram correspond to non-zero values, and the white cells indicate zero values.