Measuring Physical Plausibility of 3D Human Poses Using Physics Simulation

TL;DR

This paper introduces physics simulation-based metrics to evaluate the physical plausibility and stability of 3D human poses, addressing limitations of existing joint error metrics and improving assessment of motion realism.

Contribution

It proposes two novel physics-based metrics for plausibility and stability, and demonstrates their effectiveness on state-of-the-art pose estimation methods using the Human3.6m dataset.

Findings

Physics-based metrics correlate with existing plausibility measures

Metrics effectively evaluate stability during motion

Proposed approach enhances assessment of 3D human pose realism

Abstract

Modeling humans in physical scenes is vital for understanding human-environment interactions for applications involving augmented reality or assessment of human actions from video (e.g. sports or physical rehabilitation). State-of-the-art literature begins with a 3D human pose, from monocular or multiple views, and uses this representation to ground the person within a 3D world space. While standard metrics for accuracy capture joint position errors, they do not consider physical plausibility of the 3D pose. This limitation has motivated researchers to propose other metrics evaluating jitter, floor penetration, and unbalanced postures. Yet, these approaches measure independent instances of errors and are not representative of balance or stability during motion. In this work, we propose measuring physical plausibility from within physics simulation. We introduce two metrics to capture the physical plausibility and stability of predicted 3D poses from any 3D Human Pose Estimation model. Using physics simulation, we discover correlations with existing plausibility metrics and measuring stability during motion. We evaluate and compare the performances of two state-of-the-art methods, a multi-view triangulated baseline, and ground truth 3D markers from the Human3.6m dataset.