ViSkin: Physics-Based Simulation of Virtual Skin on Personalized Avatars

We introduce ViSkin, a biomechanically principled approach to simulate skin mechanics on personalized avatars. Our model captures the salient characteristics of human skin, i.e., nonlinear stretching properties, anisotropic stiffness, direction-dependent pre-stretch, and heterogeneous sliding behavior. In particular, we introduce a novel representation of Langer lines, which describe the distribution of principal material directions across the human body. We further propose an optimization-based approach for inferring spatially-varying pre-stretch from motion capture data. We implement our new model using a computationally efficient intrinsic representation that simulates skin as a two-dimensional Lagrangian mesh embedded in the three-dimensional body surface. We demonstrate our method on a diverse set of body models, shapes, and poses and compare to experimentally-obtained skin motion data. Our results indicate that our method produces smoother and more plausible skin deformations than a baseline method and shows good accuracy compared to real-world data.