Setting up and solving a physically-based animation proceeds as follows:

- Create a model with physical attributes: mass, moment of inertia, elasticity, etc.
- Derive differential equations by applying the laws of Newtonian physics.
- Define initial conditions, i.e., initial velocities and positions.
- Supply functions for external forces (possibly via keyframing).
- Solve the differential equations to derive animation, i.e., motion of all objects in scene as a function of time.

- During solution of the differential equations we have to be prepared to deal with discontinuities due to collisions.
- We will discuss the simulation of spring-mass and point mass models.
- Both have useful applications and are relatively simple to simulate.

CS488/688: Introduction to Interactive Computer Graphics

University of Waterloo

Computer Graphics Lab