Creating An Animation Program Alice

Recall from last lecture We began the animation creation process We introduced the concept of storyboard We will continue using the example presented last lecture

Step 2: Implementation Implementing an animation requires Setting Up the Initial Scene in Alice Writing the Program (Script)

Create Initial Scene

Techniques and Tools Mouse used to set up the initial scene approximately position objects in the scene Camera Navigation is used to set the camera point of view Drop-down menu methods are used to resize objects more precisely position objects in the scene Scene Editor's Layout Manager is used to obtain specific alignments position one object relative to another object

Writing A Program "Writing" a program (script) a list of instructions to have the objects perform certain actions in the animation

Writing the Program Our planned storyboard (to-do list) is: The idea now is to translate the design steps to program instructions. Snowman turns to face snowwoman. Snowman “makes eyes” and calls out to snowwoman. Snowwoman turns around.

Translating the Design Some steps in the storyboard can be written as a single instruction The snowman turns to face the snowwoman Other steps are composite actions that require more than one instruction The snowman tries to catch the snowwoman’s attention is two actions Snowman says “ahem” Snowman raises and lowers his eyes

Actions Sequential Some actions occur one after the other first step (snowman turns to face snowwoman) second step (snowman tries to get snowwoman’s attention) Simultaneous Other actions occur at the same time Snowman says "Ahem" and while simultaneously blinking his eyes

Action Blocks in Alice Sequential Action Block Simultaneous Action Block

Write the Animation Program Will develop in class.

Coding the first 2 steps Things to note: Nesting of DoTogether and DoInOrder blocks Arguments for the move instruction direction distance

Testing An important step in creating a program is to run it – to be sure it does what you expect it to do. We recommend that you use an incremental development process: write a few lines of code and then run it write a few more lines and run it write a few more lines and run it… This process allows you to find any problems and fix them as you go along.

Comments While Alice instructions are easy to understand, it is often desirable to be able to explain (in English) what is going on in a program We use comments to explain to the human reader what a particular section of code does

Notes: 1) Comments appear in green 2) Alice ignores comments. 3) Comments make the program easier to read.

In the previous example, the comment described a large block of program code. Comments also can be used for a small subsection of the program code.

Assignment Read Chapter 2-2, A First Program Read Tips & Techniques 2, Orientation and Movement Instructions

Lab Lab 2-2