A real 6-degree-of-freedom rigid-body physics simulation of a quadrotor: gravity, motor thrust, drag, and a cascaded PID flight controller, all integrated step-by-step — not a scripted animation. The battery model is validated against six real commercial drones' published specs. "Take a fix" calls a real backend running OpenCV/ORB computer-vision feature matching against a synthetic satellite-style map, to recover the drone's position from its simulated camera view — the same way real GPS-denied drone navigation works.
Try this: tap Cut motors mid-flight to watch gravity actually take over — the controller normally cancels it perfectly, every instant, which is exactly why you'd never otherwise see it doing anything at all.
The buildings and balls scattered around are real physics objects too — momentum-conserving collisions, not animations. Fly into a ball and watch it actually get knocked away (lighter balls fly further); fly into a building and the drone gets physically blocked, not clipped through.