MaskedMimic：通过遮罩运动修补实现统一的基于物理的角色控制

MaskedMimic: Unified Physics-Based Character Control Through Masked Motion Inpainting

September 22, 2024

作者: Chen Tessler, Yunrong Guo, Ofir Nabati, Gal Chechik, Xue Bin Peng

cs.AI

摘要

打造一个单一、多用途的基于物理的控制器，能够为交互式角色赋予生命，涵盖广泛的场景，代表了角色动画领域的一个激动人心的前沿。理想的控制器应该支持多样的控制模式，比如稀疏目标关键帧、文本指令和场景信息。虽然先前的研究提出了基于物理模拟、场景感知的控制模型，但这些系统主要集中在开发专门针对狭窄任务和控制模式的控制器上。本文提出了MaskedMimic，这是一种新颖的方法，将基于物理的角色控制问题形式化为一般的运动修复问题。我们的关键洞察是训练一个统一的模型，从部分（遮罩）运动描述中合成动作，比如遮罩关键帧、物体、文本描述或二者的任意组合。通过利用运动跟踪数据并设计可扩展的训练方法，有效地利用多样的运动描述生成连贯的动画。通过这一过程，我们的方法学习到一个基于物理的控制器，提供直观的控制界面，无需为所有感兴趣的行为繁琐地设计奖励机制。所得到的控制器支持广泛的控制模式，并实现了不同任务之间的无缝过渡。通过运动修复统一角色控制，MaskedMimic创造了多才多艺的虚拟角色。这些角色可以动态适应复杂场景，并根据需要组合各种动作，实现更具交互性和沉浸感的体验。

English

Crafting a single, versatile physics-based controller that can breathe life into interactive characters across a wide spectrum of scenarios represents an exciting frontier in character animation. An ideal controller should support diverse control modalities, such as sparse target keyframes, text instructions, and scene information. While previous works have proposed physically simulated, scene-aware control models, these systems have predominantly focused on developing controllers that each specializes in a narrow set of tasks and control modalities. This work presents MaskedMimic, a novel approach that formulates physics-based character control as a general motion inpainting problem. Our key insight is to train a single unified model to synthesize motions from partial (masked) motion descriptions, such as masked keyframes, objects, text descriptions, or any combination thereof. This is achieved by leveraging motion tracking data and designing a scalable training method that can effectively utilize diverse motion descriptions to produce coherent animations. Through this process, our approach learns a physics-based controller that provides an intuitive control interface without requiring tedious reward engineering for all behaviors of interest. The resulting controller supports a wide range of control modalities and enables seamless transitions between disparate tasks. By unifying character control through motion inpainting, MaskedMimic creates versatile virtual characters. These characters can dynamically adapt to complex scenes and compose diverse motions on demand, enabling more interactive and immersive experiences.