Creating An AnimationProgram

Alice

Recall from last lecture

We began the animation creation processWe 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 AliceWriting the Program (Script)

Create Initial Scene

Techniques and ToolsMouse used to

set up the initial sceneapproximately position objects in the scene

Camera Navigation is used toset the camera point of view

Drop-down menu methods are used to resize objectsmore precisely position objects in the scene

Scene Editor's Layout Manager is used toobtain specific alignmentsposition 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)

SimultaneousOther 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