An anatomy-based approach to human muscle modeling and deformation

Muscle simulation is an important component of human modeling, but there have been few attempts to demonstrate, in three dimensions and in an anatomically correct way, the structures of muscles and the way in which these change during motion. This paper proposes an anatomically-based approach to muscle modeling that attempts to provide models for human musculature based on the real morphological structures. These models provide a good visual description of muscle form and action and represent a sound base from which to produce further progress toward medically accurate simulation of human bodies. Three major problems have been addressed: geometric modeling, deformation, and texture. To allow for the wide variety of deformable muscle shapes encountered in the body, while retaining as many of their common properties as possible, the geometric models are classified into several categories according to the characteristics of their structures and actions. Within each category, the model for each muscle has an efficient structural form, created using anatomical data. Deformation is also performed on the basis of the categories, with all models within each category sharing the same deformation scheme. The categories cover both general and special cases. The result is an efficient, anatomically accurate muscle representation that is specifically designed to accommodate the particular form of deformation exhibited by each individual muscle. Interactions between muscles are also taken into account to avoid penetration occurring between adjacent muscles in our model. To provide a suitable visual effect, the muscle texture is generated directly on the model surface. The textures and colors are obtained from anatomical data via image analysis. Some results are presented on the geometric modeling, the deformation, and the texture of muscles related to the lower limb.