What is ai4animationpy?

AI4AnimationPy is a Python framework from Meta's FAIR research group for creating character animation using neural networks. It brings the ideas from an earlier project called AI4Animation, which was built on the Unity game engine, into plain Python, so researchers no longer need Unity to process motion data, train models, or run inference. The framework lets you train neural networks directly on motion capture recordings of people or animals moving, and then use those trained networks to generate new, believable movement for a character. Everything, from training to visualizing the result, runs inside the same Python environment using NumPy and PyTorch, so there is no need to switch between separate tools or export models through extra conversion steps just to see how they behave. It borrows structural ideas from game engines, using an entity component system and an update loop, so the codebase should feel somewhat familiar to anyone who has worked with game development before, even though it is aimed at animation researchers rather than game developers. It can run with its own built in real time renderer for visualization, in a headless mode for training on a server without any graphics, or in a manual mode where the user controls exactly when updates happen. Supported features include inverse kinematics for realistic limb movement, a math library for working with skeletons and joint rotations, and importers for common motion file formats such as GLB, FBX, and BVH, which can be converted into the framework's own internal motion format. A command line tool is included for converting entire folders of motion files at once. The project includes demo videos and a web based demo, along with full documentation covering installation and quick start steps. It is released under a Creative Commons Attribution NonCommercial license, meaning it can be used and shared for non commercial purposes such as research and learning, but not for commercial products without separate permission.