You now know how to simulate rigid body motion, but how do you simulate the motion of deformable bodies such as ropes and clothes, whose shapes can change? There are various approaches to do that, but we'll introduce one particular approach based on the spring physics that we covered in Chapter 8. Let's begin by a brief recap of the main principles and formulas of spring physics and discussion of how they can be applied to model deformable bodies.
The basic modeling approach is to represent a deformable extended object as a series of particles with mass joined together by virtual springs. Hence we generally refer to such models as mass-spring systems. As an illustration of the method, consider the simple ...