Figure 3

The 3D stick figure model used for representing human pose and limb orientation represented as direction cosine. (a) Ten principal joints corresponding to the markers used in motion capture are used for 3D stick figure. (b) Limb orientation is represented with the direction cosines of angles (${\theta }_l^x,{\theta }_l^y,{\theta }_l^z$) between the limb l and the axes.