BB84 Quantum Key Distribution 3D — Polarization Filters

This 3D scene turns the BB84 protocol into a beamline you can orbit around: Alice's transmitter fires polarized photons down the line toward Bob's detector, which spins a real polarization-filter disk to a fresh random basis before every arrival. The physics driving each photon's fate is genuine — a filter aligned with the photon's own polarization always passes the correct bit through, while a misaligned filter forces a true random collapse, 50/50, matching real quantum measurement statistics rather than a scripted animation. Insert Eve's intercept-resend station partway down the beam to see an eavesdropper's fundamental problem in 3D: she must guess a measurement basis too, gets it wrong half the time, and every wrong guess re-emits the photon in the wrong polarization — producing the same ~25% quantum bit error rate that gives her away on a real quantum channel.