Realistic simulation is critical for applications ranging from robotics to animation. Traditional analytic simulators sometimes struggle to capture sufficiently realistic simulation which can lead to problems including the well known "sim-to-real" gap in robotics. Learned simulators have emerged as an alternative for better capturing real-world physical dynamics, but require access to privileged ground truth physics information such as precise object geometry or particle tracks. Here we propose a method for learning simulators directly from observations. Visual Particle Dynamics (VPD) jointly learns a latent particle-based representation of 3D scenes, a neural simulator of the latent particle dynamics, and a renderer that can produce images of the scene from arbitrary views. VPD learns end to end from posed RGB-D videos and does not require access to privileged information. Unlike existing 2D video prediction models, we show that VPD's 3D structure enables scene editing and long-term predictions. These results pave the way for downstream applications ranging from video editing to robotic planning.

通过视觉粒子动力学以及端到端学习的方式，我们提出了一种从观测数据中直接学习模拟器的方法，避免了对特殊的信息的依赖，从而实现更加真实可信的仿真。这一方法的3D结构使得场景编辑和长期预测成为可能，为视频编辑和机器人规划等应用提供了新的路径。

从RGB-D视频中学习基于粒子的3D模拟器