PhysGen: Rigid-Body Physics-Grounded Image-to-Video Generation
Authors: name: Shaowei Liu, name: Zhongzheng Ren, name: Saurabh Gupta, name: Shenlong Wang

We present PhysGen, a novel image-to-video generation method that converts a
single image and an input condition (e.g., force and torque applied to an
object in the image) to produce a realistic, physically plausible, and
temporally consistent video. Our key insight is to integrate model-based
physical simulation with a data-driven video generation process, enabling
plausible image-space dynamics. At the heart of our system are three core
components: (i) an image understanding module that effectively captures the
geometry, materials, and physical parameters of the image; (ii) an image-space
dynamics simulation model that utilizes rigid-body physics and inferred
parameters to simulate realistic behaviors; and (iii) an image-based rendering
and refinement module that leverages generative video diffusion to produce
realistic video footage featuring the simulated motion. The resulting videos
are realistic in both physics and appearance and are even precisely
controllable, showcasing superior results over existing data-driven
image-to-video generation works through quantitative comparison and
comprehensive user study. PhysGen's resulting videos can be used for various
downstream applications, such as turning an image into a realistic animation or
allowing users to interact with the image and create various dynamics. Project
page: https://stevenlsw.github.io/physgen/