arxiv.orgpaper

PhysStream: Streaming Physics-Grounded Video Generation with Structured Scene Memory and Fine-Grained Motion Control

PhysStream is an autoregressive image-to-video generation model that maintains structured scene memory (positional maps and object tracking maps derived online from previously generated frames) and supports fine-grained, mid-generation motion control via sparse velocity-increment signals encoding physical quantities. Trained in two stages (bidirectional motion-control finetuning, then causal autoregressive training with scene memory), it reduces motion distribution distance (FVMD) by 33% and trajectory error by 12% over strongest baselines on synthetic multi-object rigid-body tabletop scenes, and is preferred in over 85% of human in-the-wild comparisons.