1. Video 1. Polar flocks were observed when filaments were restricted to interpenetrate each other. $r_{\mathrm{shift}} = 0$, $\varepsilon = 1$ in $U_{\mathrm{WCA}}$. The simulation box size $L_x = 250$, area fraction $\phi = 0.5$. Total number of chains $N = 2016$. The color wheel legend indicates the filament orientation which is the average tangent orientation of each bead of the filament. This video corresponds to Fig. 1A of the main text.
2. Video 2. Changing the energy cost $\varepsilon$ of filaments to interpenerate, we obtain different states as shown in this video. This video corresponds to Fig. 2 of the main text.
3. Video 3. Video showing the time-evolution of a system initialized in the isotropic state reaches a LRO polar steady state passing the LRO nematic transient state. This video corresponds to Fig. 5A of the main text.