InfiniDreamer: Arbitrarily Long Human Motion Generation via Segment Score Distillation

We present InfiniDreamer, a novel framework for generating human motions of arbitrary length. Existing methods typically produce only short sequences, limited by the scarcity of long-range motion data. To address this, InfiniDreamer first generates short sub-motions for each textual description, then coarsely assembles them into a long sequence using randomly initialized transition segments. To refine this coarse motion, we introduce Segment Score Distillation (SSD)---an optimization-based approach that leverages a pre-trained motion diffusion model trained solely on short clips. SSD iteratively refines overlapping short segments sampled from the full sequence, progressively aligning them with the pre-trained short motion prior. This procedure ensures local fidelity within each segment and global consistency across segments. Extensive experiments demonstrate that InfiniDreamer produces coherent, diverse, and context-aware long-range motions without requiring additional long-sequence training.