Marc Raynaud 🇫🇷

🚨 Someone open sourced an entire animal. Not a model of an animal. The animal. A fruit fly, rebuilt joint by joint from microscopy, that walks, grips, flies and lands inside a physics engine running on your laptop. It's called flybody. Built by Google DeepMind and HHMI Janelia, published in Nature, and sitting on GitHub under Apache 2.0 right now. What's actually inside: A full body in MuJoCo. Legs, wings, head, abdomen, every joint articulated and physically simulated. A 59-dimensional action space in the walking task alone. That is how many things a network has to coordinate for the fly to take one step. Leg adhesion, so it actually grips surfaces instead of sliding off them like a game asset. Ready-made RL environments: walking imitation, free flight, and vision-guided flight where the policy flies on what the fly sees. The whole thing is Python. Clone it, open MuJoCo, and the fly is on your screen. And the part that got me: Nobody animated any of this. You hand the body to a reinforcement learning agent and it discovers how to move it. Same loop as a robot arm, except the robot is a bug and the reward is staying airborne. Which means people are now training it to do things no fly has done in 100 million years of evolution. 525 stars. Apache 2.0. Zero dollars.