2010

Table Of Contents
Lesson 1: Creating a simple expression
Introduction
This lesson introduces you to some basic concepts regarding the creation and
editing of expressions. You learn how to:
Use the expression editor to create and edit expressions.
Control both single and multiple attributes of objects in your scene.
Creating expressions to control a single attribute
In the following steps, you create a default sphere and write an expression to
increase its Scale Y attribute as the animation time increases during playback.
To create an expression
1 Make sure youve done the steps in
Preparing for the lessons on page 626.
2 Create a NURBS or polygonal sphere with an X scale, Y scale, and Z scale
equal to 1. Rename the sphere Ball. (Upper and lower case text is
important)
3 With Ball selected, choose Window > Animation Editors > Expression
Editor.
4 In the Expression Name box, you can optionally enter an expression
name, for instance, ScaleBallHeight.
If you write several expressions in the same scene, giving each a name
might make it easier to find the desired expression if you decide to alter
it later. If you dont provide a name, the expression receives a default
name, for instance, expression1.
Lesson 1: Creating a simple expression | 627