标签：#worldmodels

Video AI systems consistently fail to track what happens when the camera looks away: when a scene pans away from an object in motion and returns, current models re-render the object in its original position rather than showing the logical result of off-screen change. Scaling to more parameters makes this failure worse, not better, according to WRBench , a new benchmark that tests what researchers call "world model reliability." The benchmark presents AI video systems with scenes where something happens off-screen — the camera pans away while an object is in motion, or while a light changes, or while an open door should stay open — then pans back to see what the system believes should have happened. A system that genuinely models the world would track what occurred during the off-screen interval. Current systems mostly don't. Key facts What: A new benchmark tests whether video AI systems can track what happens to parts of a scene the camera isn't currently showing. Across 23 models, the answer is mostly no — and making the models larger made the problem worse, not better. When: 2026-06-19 Primary source: read the source (arXiv 2606.20545) The benchmark covers twenty-three different video generation models and nearly ten thousand video clips across six categories of off-screen change, each designed to test a different aspect of world continuity: objects in motion, light sources changing, object states such as open or closed doors, and several others. This gives a comprehensive picture rather than a single narrow test. The most striking finding is the scaling result. The researchers tested one of the more capable video generation systems at two different sizes: a smaller version and one with more than ten times as many parameters. More parameters didn't help. Scaling made the off-screen tracking problem measurably worse. The larger model produced more realistic-looking frames, but it was less accurate about what should have happened to the parts of the scene it wasn't