Illustration of the cosmic filament network identified by DisPerSE at z = 1 in TNG50-1. Blue lines show the filaments in a 20 cMpc thick slice, while purple and green points mark maxima and saddle points, respectively. The background image shows the DM surface density projected over the same slice. Our analysis is restricted to the area enclosed by the white box, excluding the outer ∼5% of the simulation volume to avoid boundary effects.