Simulation

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

1. Create a model with physical attributes: mass, moment of inertia, elasticity, etc.
2. Derive differential equations by applying the laws of Newtonian physics.
3. Define initial conditions, i.e., initial velocities and positions.
4. Supply functions for external forces (possibly via keyframing).
5. 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.