Flow Matching for Text-Driven 3D Human Motion Generation: Towards High-Quality, Diverse, and Natural Synthesis
The generation of human body motions guided by descriptive text has a wide range of applications, including robotics, augmented and virtual reality, and entertainment. However, achieving human motions that exhibit both diversity and fidelity to the input text while maintaining high naturalness and avoiding artifacts remains a challenging task. This challenge stems from the need to go beyond merely retrieving motions similar to the text or performing simple operations on recorded human movements; instead, it requires demonstrating creativity by synthesizing novel movements. Generative models based on artificial intelligence thus offer a promising approach to address this challenge; these methods, including Diffusion Models, VAEs, GANs, and their combinations, have been explored for this purpose. Despite advances, challenges have remained, including artifacts, involuntary movements, and difficulties maintaining high fidelity to the text. Some approaches suggest post-processing generated motions with filters to reduce jitter, but this often compromises quality or coherence. More recently, Flow Matching (FM) models have emerged as a promising generative approach across many domains, offering simpler mathematics and faster generation. FM trains a neural network to transform, via a vector field, a simple distribution corresponding to noisy data into the complex distribution of the training data. Motivated by their characteristics, we have adopted FM in this work. However, the high jitter caused by limited computational resources imposes challenges on our human motion generation task. To address this, we proposed a novel training and sampling strategy. This strategy allows the model to first estimate noise-free data before defining the vector field for generation, rather than simulating the vector field directly. Results demonstrate high-quality motion generation, improved diversity and naturalness (low jitter), and more efficient resource utilization. On the HumanML3D and KIT datasets, our method achieves top jitter reduction on KIT and near-state-of-the-art reduction on HumanML3D, while maintaining an optimal fidelity-naturalness balance and avoiding post-processing.