Unit 1Programming in Alice & Java

Day 1: Introduction to Programming Logic

Objective: Understand the need for step-by-step logic;

Basic working of a computer

Essential Skill: Gather and organize information and data

Warm-up: Write the steps or directions for making a

peanut butter and jelly sandwich.

Computers just follow instructions!

Can store and manipulate data

Has basic operations

Add/subtract/multiply/divide

Move

Determine which of 2 numbers is bigger

Instructions must be put together in a program

Definitions and Helpful Tools

Algorithm: a set of well-defined, logical steps that must be

taken in order to perform a task

Pseudocode: steps written in English

Ex: the directions you wrote for the sandwich

Activity: Write pseudocode for calculating someone’s weekly

salary

Flow chart: diagram showing steps (example on next slide)

Storyboard: pictures and descriptions of actions you want to

take place

Especially useful for animation/games/simulations

Flow Chart Example:

START

Take out 2

slices of

bread

Take out 1

slice of ham

Place ham

squarely on 1

slice of bread

Enough

ham?

No Yes

Take out 1

slice of

cheese

Place cheese

squarely on

top of ham

Enough

cheese?

No Yes

Put 1 tsp of

mustard on

top of cheese

Spread with

knife to cover

cheese

Place other

piece of bread

squarely on top

Slice in half

STOP

Languages

A computer uses the language binary

On/off switch

1’s and 0’s

Programming languages:

More like English

Must have an associated compiler

Designed to be used for various tasks

Must be written exactly right or the compiler can’t change it to

machine code

Two Parts to Programming

Logic

Break tasks down into steps

Figure out the order

Syntax (rules)

What words to use

Symbols ie. {}, ; ()

Day 2: Introduction to Alice

Objective: Understand what Alice is and how it is used

Essential Skill: Gather and organize information and data

Warm-up: Write the psuedocode for cooking scrambled eggs

What is Alice3?

Designed to teach programming theory without the

complex language and rules of production languages

You can place objects from a gallery into a virtual world

and then create programming statements to animate the

objects in the world

Allows the user to learn how to program in the context of

animation, simulation, storytelling, and building short

games

User creates “rough drafts” of animations, games

simulations, and film-like stories

A Brief Tour: An overview of Alice3

Start Alice3 and select a template

Now this screen should start:

Code editorScene view

Methods panel

Control tiles

Parts of the screen:

Methods panel:

Contains a set of tiles

Each tile describes an action an object can perform (or have

performed on it)

Code Editor:

Where the program for the animation or game is written

Scene View:

Where the world is set up for the animation or game

Scene Editor:

Click on Setup Scene to go to the Scene Editor

This is where the scene for the animation or game is created

Alice World

An Alice project creates a virtual world

Primary component of a world is a scene

The current scene is known as the “this” scene

Components of a scene:

always has a camera and a ground surface (which may be

grass, sand, rocks, or even water)

Other objects may be added to a scene

Scene Editor

Scene setup panel

Gallery panel, organized by class hierarchy

Scene Editor:

Click on Setup Scene to go to the Scene Editor

This is where the scene for the animation or game is created

Classes

Each 3D model is a pre-written class

In Alice, a class defines

A plan for constructing a new object in an Alice scene

Actions an object of that class can perform

Classes

An Alice class is similar to an architect's blueprint for

building a house

Not the actual house -- just a plan for constructing a

new house, based on a sketch of what it will look like

Objects

An instance of a class is an object

The gallery tabs provide alternate organization

In these panels, classes are organized based on how objects

move around in a scene

Each class folder is like a drawer in a file cabinet, where all

classes of the same type are stored.

Flyer (has wings and can fly)

Biped (walks on 2 legs)

Quadraped (walks on 4 legs)

Swimmer (lives in water, swims)

Adding Objects

Select class folder for the type of object that you wish to

add to the scene

Lets use a Quadruped!

Within the Quadruped folder are classes of objects that

move around on 4 legs.

Each image is labeled with the name of the class and

shows a preview for a new object of that class.

Adding Objects

Click on the image to select one of 10 versions of objects that can be

created by the DragonBaby class

The DragonBaby class has 10 different paint resources

Click on one of the images to select one of the paint resources

Alice will automatically create a new DragonBaby object and paint it

with the selected paint resource

Enter a name for the new DragonBaby object

10 different versions of DragonBaby objects

Terminology: Instance/Object

We have constructed a new instance of the DragonBaby

class and identified it with the name izzy

We say an instance of a class is an object

Naming Conventions

Meaningful names

Most languages do not allow spaces so we will not use them

Pascal Case

Each word starts as upper case

Used for classes

Ex. IceSkater, DragonBaby

Camel Case

First word lower case, other words upper case

Used for objects – instances of a class, and methods

Ex. blackBeauty, izzyTheBabyDragon

Alternate Technique

A new object may be added to a scene by clicking and

dragging the image into the scene

The dialog box for naming the object will still pop up, in

the same way as before

Objects of the Same Class

A scene may have more than one object of the same class

Example:

Izzy and Josh are two different objects (instances) of

the same DragonBaby class.

Different objects have different names and may have

different colors, sizes, and other properties.

Scene Editor - Object tree

In the scene editor, Alice generates an object tree to show

a list of all objects in this scene

Click on Edit Code to return to the Code Editor

Code Editor – Object list

In the code editor, Alice generates a corresponding list of

objects in a pull-down menu

Object menu

Object tree

Ancestry

Each object in the scene is an instance of a class

that belongs to a family of classes.

The class’s ancestry is shown in the methods

panel

Inheritance: Order

Ancestry can be ordered from specific to most

generic (similar to youngest to oldest)

The ancestry list tells you that izzy is an instance

of the DragonBaby class and thus she inherits all

properties and methods of the Quadruped class

Class Hierarchy

In computer science, we often use a more abstract

representation of class inheritance, known as a class hierarchy

Model

|-JointedModel

├ SQuadruped

├ Quadruped

├ DragonBaby

Note that Izzy is NOT specified in the class hierarchy because

Izzy is an object, NOT a class.

Not shown in Methods Panel

Classwork:

Now you have time to play!

Create a world and add some objects

Explore the gallery to see what classes are available

Check out any other features of the scene editor

Objective: Learn how to move objects in Alice3

Essential Skill: Gather and organize information and data

Warm-up: Create a scene with the Sea Floor template and

add an instance of the DesertTortoise class (in the

quadruped folder)

Day 3: Motion and Rotation

Alice Object Properties

An Alice object:

is located in a 3D world, positioned at (x, y, z)

has 3 dimensions(height, width, depth)

can move in 6 directions

An object’s center is its pivot point (around which it moves and rotates)

The center of an object is usually where it stands on the ground

up

right

forward

down

left

back

center

Describing an Objects Location

Position: relative to the ground’s origin (x,y,z)

Orientation: an object’s sense of its own forward and up directions

(19, 15, -20)

(0, 0, 0)

Translational Motion

Translational motion changes the location of an object in the world

The direction of translational motion is stated relative to the

orientation of the object

Six possible directions: left, right, up, down, forward, backward

Example: Move forward

object’s new position is now “in front of” its previous position

(relative to the object’s own sense of forward)

object’s position (x,y,z) coordinate has changed; it’s sense of “up”

has not changed.

Rotational Motion

Changes the orientation of an object in the world

There is no change of position of the object

Object’s center acts as its pivot point for rotation

Two forms of rotational motion:

Turn: forward, backward, left, right

Roll: left, right

Example: Roll right

Object’s new position is now rotated to the right of its original

position (relative to the object’s own sense of right)

Object’s location (x,y,z)-coordinate has not changed. It’s sense of

“up” has changed but its sense of forward has stayed the same

Lets try it! Go back to your warmup

You will see you have handles to control the movement:

Default allows Left/Right and Forward/Backward movement

Rotation allows Forward/Backward and Left/Right turn and Left/Right roll

Translation allows Up/Down, Left/Right and Forward/Backward movement

Resize Allows you to increase or decrease the size of the object

Mouse and Keyboard Commands

Use mouse to drag object left ↔ right or forward ↔ backward

Hold shift key and drag for up ↔ down

Hold ctrl key (option key, Mac) for rotation

Join Motion

Objects often (not always) have internal joints that can be

animated to control subparts of the model.

A joint connects a subpart of the body to the rest of the body

A joint can be turned or rolled but cannot be moved

Biped X-Ray

Quadruped X-Ray

Subparts

A subpart may be connected to another subpart

Rotating one subpart may also rotate other subparts

Examples:

Turning the left shoulder joint will also turn the entire arm of the alien, including the forearm, wrist, hand, fingers, etc.

Turning the left elbow joint will also turn the alien’s forearm, wrist, hand, fingers, etc.

Subparts

The orientation of a subpart is not necessarily the same as the

orientation of the whole object

A subpart cannot be moved

A move would detach the joint (and its connected subpart) from rest of

the model, so a move action is NOT allowed for a subpart of an object.

Rotational Motion: Joint/Subpart

A subpart’s joint acts as its pivot point for rotation of the subpart

To access a joint, click on the arrow next to the object’s name in the object list

Red Handle: Turns joint forward and backward

Green Handle: Turns joint left and right

Blue Handle: Rolls joint left and right

Example!

Look at the DesertTortoise’s subparts

Select the FrontRightKnee

You can now move that subpart

Play around a little

One Shots

Classwork

Now you have time to play!

Create a world

Add some objects

Move them around

Resize them

Try moving subparts

Tip: Don’t forget you have an undo button!

Day 4: Classwork 1.1

We will do this together!

Write up posted on website so you can follow along

Day 5: Project 1.1

Write up posted on website

Day 6: Quiz 1.1

20 points

Multiple choice

True/False

Short Answer

Material from PowerPoint and Class Discussions