Animation Programs

Alice

Overview

2-step process for creating animationsStep 1: Design

Step 2: Implementation

Step 1: Design

Decide on the problem to be solvedOften the problem to be solved is given to you by your instructor, team leader, etc.

Other times, you get to make it up!

We will practice both

Design a solution We will use a storyboard design

An example problem (scenario)

The scenario is: Several snow-people are outdoors, on a snow-

covered landscape. A snowman is trying to meet a snowwoman who is talking with a group of her friends (other snowwomen.) He says “Ahem" and blinks his eyes, trying to get her attention.

The problem is: How can we create this animation?

Designing a solution

First decide on the objects that will be in the scene.Then, create a storyboard.

A "storyboard" is a representation of what actions are going to take place in the animationA storyboard can take two forms

sketches textual "to do" lists

Sketch Objects: A snowman and a snowwoman (and possibly other snowpeople)

Opening Scene: a snowy scene

A quick sketch:

A Storyboard

Initial scene Snowman tries to catch snowwoman’s attention

Snowwoman looks around

Storyboard in Text Form

Animation Artists (for example, at Disney or Pixar Studios) sketch their storyboardsYou might not have such expertise, so here is a textual form that can be used:

This is like a "to-do" list.

Snowman turns to face snowwoman.

Snowman “makes eyes” and calls out to snowwoman.

Snowwoman turns around.

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 is used toset 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 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

Assignment

Read Chapter 2 sections 1 and 2 Scenarios and Storyboards

A First Program

Read Tips & Techniques 2 Orientation and Movement Instructions

Lab 2

Exercises from 2-1 and 2-2