Long video generation stops forgetting with time: Smart addresses a fixed-size slot memory by camera pose and still recalls old scenes beyond its training horizon
Long-horizon video generation has traded between two kinds of memory: explicit geometric caches recall a place by location but grow with the scene, while recurrent memories stay constant-size yet let old observations fade with time. Smart turns a fixed-capacity slot memory into one addressed by camera pose, so writes and reads depend on where something was seen rather than how long ago, and a diffusion generator uses the memory's confidence to decide where to trust it. On long trajectories in Memory Maze and Minecraft it keeps high-fidelity recall far beyond its training horizon at constant memory and per-step cost.