Solving for muscle blending using data

• Published in: Computers & graphics Vol. 92; pp. 67 - 75
• Main Authors: Dinev, Dimitar, Guo, Wenxian, Kadleček, Petr, Kavan, Ladislav
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.11.2020; Elsevier Science Ltd
• Subjects: Anatomical models; Blending; Computer graphics; Facial animation; Mathematical models; Muscles; Parameterization; Parameters; Physics-based simulation; Facial animation; Physics-based simulation; Anatomical models
• ISSN: 0097-8493; 1873-7684
• DOI: 10.1016/j.cag.2020.09.005

•Anatomical muscle models are important for facial simulation and animation.•Parametrizing the muscle activations remains a challenge.•Solving for the blending geometry of muscles reduces the space of activations.•Blending geometry information can be reused to fit new expression scans. [Display omitted] Modeling of the human face is a challenging yet important problem in computer graphics. Building accurate muscle models for physics-based simulation of the face is a problem that either requires a lot of manual effort or drastic over-parameterization of the muscles to achieve desirable results. In this work, we reduce the number of parameters required to build personalized muscle models by taking into account the blending of the fine muscles and passive tissue when we solve for the muscle activations. We begin by adapting an anatomical template model to a neutral scan of a subject. Then, we solve an inverse physics problem using several scans simultaneously to solve for both the muscle activations and the geometry matrix representing blending of the muscles. Finally, we demonstrate that this geometry matrix can be used on new, previously unseen scans to solve for only the muscle activations. This greatly reduces the number of parameters that must be solved for compared to previous works while requiring no additional manual effort in constructing the muscles.