It's like its simulation model is confined to the renderable area. At the cost of increased computation, it would not be hard to generalize the technique to rendering a sphere centered around the POV to keep some of those artifacts at bay; however, the fundamental limitation of "object permanence" remains if objects can evolve chaotically as soon as they are blocked from view by another object. For that to be made stable, you really need a whole 3D model of the scene, and the cost increase there might be huge.

> While it can maintain coherent environments over short sessions, visual details and object permanence can still shift or drift over time—especially as a simulation runs longer, after multiple complex prompt edits, or when navigating throughout the scene. Complex physical interactions, real-time audio accuracy, rendering legible text, spatial accuracy, and long-term consistency are active areas of ongoing research.

> For that to be made stable, you really need a whole 3D model of the scene, and the cost increase there might be huge.

I suspect it is, because the 2D -> 3D models I've seen are terrible, but more importantly the 2D -> 3d models are terrible. Noteworthy because I suspect the number of people who have 3D scans laying around is tiny.

What you're describing is vaguely how video games work, to my understanding. There may be interesting parallels if that becomes a technique (like how distant objects are sometimes still rendered, but at a lower resolution/polygon count).

If it was actually not hard, they would have made their demo with it. I don't know the technical details, but I expect a product reveal like this to show the thing at its absolute best.