Figureure 1 · Abstract teaser and workflow of Echo-MemoryFigure 1 Abstract teaser and workflow of Echo-Memory. Given a text description, historical observations, and the camera/action state, an action world model must generate chunk-wise video while carrying memory across revisits. The figure positions Context, Compression, Spatial, and State-Space families as representative designs for preserving a revisitable world.这张图/表用于判断 Echo-Memory 的实验收益来自哪里。重点看替换、消融或跨模型设置下趋势是否一致，而不是只看单个最高分。Figureure 2 · Overview of four representative approaches to memory in action world mFigure 2 Overview of four representative approaches to memory in action world models. Under a shared video diffusion backbone and a shared camera-action interface, the approaches differ only in how historical information is stored and read. We compare four families throughout: Context, Compression, Spatial, and State-Space.这张图概括 Echo-Memory 的整体方法流程。阅读时先看模块之间传递的训练信号，再看作者如何把目标拆成可优化的子问题。
