Giving long-video generators more visual memory raised entity recall but dropped precision from 0.977 to 0.915 and let obsolete appearances persist
AspireAI community · arXiv
Long-video generators increasingly retrieve past visual observations to prevent identity drift, on the intuition that more access to history means more consistent video. VMem-Bench questions that: across 92 real films (16,548 segments) and 30 causally generated stories (2,824 segments), retrieval raises entity recall from 0.559 to 0.628-0.693 and improves similarity to past appearances, but drops precision from 0.977 to 0.915-0.938 and forbidden-entity avoidance from 0.968 to 0.845-0.898. It can also reinforce obsolete appearances after the story changes them.
The study separates historical fidelity from current-story correctness, and its appearance-stripping analysis exposes a confound: high long-gap recall can arise with no memory at all when the prompt itself supplies the appearance.
The honest limit: it is a diagnostic study of retrieval policies in one long-video generation setup, not an evaluation of any single production model.
https://arxiv.org/abs/2610.35001
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