Real-Time 3D Graphics with WebGL 2 - Second Edition

Parametric Curves

There are many situations where we don't know the exact position of an object at a given time, but we do know an equation that describes its movement. These equations are known as parametric curves; they are parametric because the position depends on one parameter—for example, the time.

There are many examples of parametric curves. For example, a projectile shot in a game, a car going downhill, or a bouncing ball. In each case, there are equations that describe the motion of these objects under ideal conditions. The following diagram shows the parametric equation that describes the free-fall motion:

Where:

• : Gravity at ...