We aim to perform unsupervised discovery of objects and their states such as location and velocity, as well as physical system parameters such as mass and gravity from video -- given only the differential equations governing the scene dynamics. Existing physical scene understanding methods require either object state supervision, or do not integrate with differentiable physics to learn interpretable system parameters and states. We address this problem through a $\textit{physics-as-inverse-graphics}$ approach that brings together vision-as-inverse-graphics and differentiable physics engines. This framework allows us to perform long term extrapolative video prediction, as well as vision-based model-predictive control. Our approach significantly outperforms related unsupervised methods in long-term future frame prediction of systems with interacting objects (such as ball-spring or 3-body gravitational systems). We further show the value of this tight vision-physics integration by demonstrating data-efficient learning of vision-actuated model-based control for a pendulum system. The controller's interpretability also provides unique capabilities in goal-driven control and physical reasoning for zero-data adaptation.

本文提出了一种基于物理-逆向图像学的方法，可以从视频中无监督地估算系统的物理参数，实现长期视频预测和基于视觉的模型预测控制，并在交互物体系统的长期未来帧预测中显著优于相关无监督方法，还实现了控制器的可解释性提供了独特的能力在目标驱动控制和物理推理方面的零数据适应。

Physics-as-Inverse-Graphics: 从视频中无监督地估计物理参数