Model-based-rl

A world model is a learned simulator. Give it a state and an action and it predicts what happens next. This write-up follows the idea from Ha and Schmidhuber's V+M+C agent through Dreamer, MuZero and TD-MPC, to Genie, Cosmos and V-JEPA, the drift that comes with imagining too far ahead, LeCun's case for predicting representations instead of pixels, and why robots need all of this.