Biomechanical modeling: Implementing line-of-action algorithm for human muscles and bones using generalized cylinders

Abstract

Computer Animation of the human body is one of the most challenging problems. In this paper, we discuss the complexity of the musculoskeletal system for the purpose of human animation. As most of the human body parts are cylindrical in nature, a Generalized Cylinder (GC) is a logical choice for modeling these parts. GCs are also well-suited for physiologic cross-sectional area analysis. The shape of a GC is modeled by a Non-Uniform Rational B-Spline (NURBS) surface or B-Spline curves. Using the B-Spline curves, we have implemented an algorithm to find the line-of-action, and the volume centroid of the muscles and bones of the upper arm. Based on the line-of-action and centroid calculations, we have proposed a novel deformation algorithm which would avoid time consuming equilibrium analysis.