🧪 Confetti Drop: Flat-Plate Aerodynamics & Tumbling (2D)

This 2D companion replaces decorative constant-speed spin with real flat-plate aerodynamics: each rectangular piece has its instantaneous relative air velocity split into a normal component and a tangential component, each carrying its own drag coefficient (a face-on plate feels far more drag than an edge-on one), and a shifting center-of-pressure lever arm couples the two into a torque about the piece's centroid. The result is genuine flutter and end-over-end tumbling that emerges from the equations rather than being animated by hand — and the aspect-ratio, air-density and wind-gust sliders visibly move each piece between steady gliding and chaotic tumbling, the same regimes real falling paper and leaves exhibit.