2011

12 In intervals of 20 keyframes, increase the gain on the red channel, so that
it is at its maximum by frame 100.
13 Play the animation.
Example: Using Functions to Drive Animation
This example shows you how pre-established functions can be used as
expressions to drive animation—see Expression Reference Tables on page 745.
The goal of this example is to create random noise using the Noise tool—see
Noise Tool on page 427. You could create the appearance of random noise by
modifying the Noise Seed attribute using periodic keyframes. However, a more
simple approach is to use a random number function. In this case, the
TrueRand function is used.
NOTE It is assumed that you currently have the Player, Schematic, and Composition
Browsers open. With the focus on Schematic, use Ctrl + N (Windows and Linux)
or Cmd + N (Mac OS) to create a new composition.
To create random noise using a random number function:
1 From the Tools tab, drag the Noise tool from the Image Generation folder
to the dependency graph in the Schematic view and connect it to the
Output node.
2 In the Player controls, change the composition's total number of frames
to 100.
3 In the tool UI, set the Fill, Start, and End color preferences.
738 | Chapter 31 Expressions