Handwritten Physics · 3D Rube Goldberg Machine Animation

An automatically looping 3D Rube Goldberg machine: a marble rolls down zig-zag ramps, topples dominoes, launches a ball via seesaw into a bucket, the bucket weight pulls a rope over a pulley to ring a bell and raise a flag—about 15–20 seconds total, then replay. Screen record at 1280×720. The prompt requires hand-written physics (no library), Three.js rendering only, fixed timestep for determinism, cinematic follow camera, and no UI. Perfect for physics education, creative coding showcase, or model evaluation.