research
The Video Critic Stopped Rewarding Stillness
A 4D reconstruction reward modeled scene dynamics instead of treating motion as geometric error.
Summary
A 4D reconstruction reward modeled scene dynamics instead of treating motion as geometric error.
Streaming video generators can learn to freeze because a rigid 3D consistency critic penalizes genuine object motion. Stream4D replaces that critic with feed-forward 4D reconstruction, adds a motion prior and retains a perceptual anchor. Across tested autoregressive backbones and horizons, the authors report better 4D reconstruction, motion retention and human-aligned preference. The abstract does not claim removal of every long-horizon artifact.
Why it matters
A 4D reconstruction reward modeled scene dynamics instead of treating motion as geometric error.
Limits and context
- The abstract does not claim removal of every long-horizon artifact.
Key claims
A 4D reconstruction reward modeled scene dynamics instead of treating motion as geometric error.
Qualification: The abstract does not claim removal of every long-horizon artifact.
Evidence: source-2026-08-22-014
Sources
- arXiv preprint 2608.19556arXiv · primary research
Corrections
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