A Beginner’s Guide to World Models

World Models are AI systems that create internal simulations of an environment to predict how it will change in response to actions, allowing an AI to "think before it acts." The guide discusses the history and state-of-the-art, including models like Google's Genie, and categorizes architectures into types like JEPA and Generative Foundation Simulators. It then provides a detailed Python tutorial for building a simple World Model using PyTorch and the Gymnasium library. The tutorial walks through preprocessing data from an Atari game, collecting game experiences in a replay buffer, and constructing the core neural network components: an encoder, a dynamics model, and a decoder.