Abstract

By simulating motion and deformation of a set of 3D characteristic curves defining surfaces, we introduce a new skin deformation technique to animate skin deformation of character models. This technique consists of two parts, representation of characteristic curves and dynamic skin deformation. The first part is to extract characteristic curves of an existing model, that is a polygon model or a NURBS model, represent the characteristic curves with time-dependent 3D trigonometric curves, and relate the surface points of the model to these trigonometric curves. The advantage of such a treatment is that it can transform an original 3D problem into a 2D problem, making it much quicker and easier to process and compute. In the second part, a vector-valued dynamic fourth-order differential equation is employed to govern the behaviour of the time-dependent 3D trigonometric curves. These dynamic differential equations incorporate both the time component and the physical properties of the material, which are given by the user. Thus, the character model can be made to animate (deform) following the user-specified behaviour parameters. Our experiments demonstrate that this technique is able to produce realistic skin deformations efficiently and avoid the undesirable skinning problems suffered by some existing skinning techniques.