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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