A wall of over a thousand thin instanced panels that flip in travelling waves — dark on the front, neon on the back — each rotating a full 0→π about its horizontal axis as a wave front sweeps past to reveal its glowing underside. Two flip waves cross the wall on different headings, and where they collide the panels lose coherence: a hashed turbulence term spins those cells out of phase so they thrash and flash hot before the waves separate and order returns.