The spear is released with speed v = 17 + 0.19 · power m/s at the chosen launch angle, then integrated frame by frame under gravity, quadratic aerodynamic drag relative to the wind, and a small velocity² lift term (the same coefficients as the 3D version):
v_rel = v_spear − v_wind
F_drag = −k·|v_rel|·v_rel (k = 0.00185)
F_lift = min(0.65, |v_rel|²·0.00048) (vertical only)
a = (0, −9.81) + F_drag + (0, F_lift)
A headwind (negative wind) increases drag opposing the throw and shortens range; a tailwind reduces relative airspeed and can carry the spear further. The target is a fixed ring — the flight ends the instant the spear's tip crosses the target's x-band within the ring radius, or when it touches the ground.
- Trajectory trail — the full flight path drawn as the spear travels.
- Target ring — a hit is registered when the spear tip passes through it; otherwise range is measured from the throw point to the landing spot.