Classes and Objects

Copyright 2014 Wanda Dann, Don SlaterAll rights reserved

An Alice World

Classes

Objects

Alice World

An Alice project creates a virtual world.The primary component of a world is the

camera view, as shown in the Scene Editor.

this

The current scene is known as “this” scene

Components of a scene 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.

Where the program for

the animation or

game is written

Code Editor

Click on Setup

Scene to go to the Scene Editor

Go to Scene Editor

Scene Editor

Where the scene for the animation or

game is created

Gallery panel, organized by class hierarchy

Video: 02. Gallery TourAn Overview of the Alice 3 Gallery and Classes

Each 3D model is a pre-written classIn Alice, a class defines

◦ A plan for constructing a new object in an Alice scene

◦ Actions an object of that class can perform

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.

An instance of a class is an objectThe following slides illustrate how to create

(construct) a new object in an Alice scene.

Gallery panels

The gallery tabs provide alternate organization schemes

Class Hierarchy• In this panel, 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)

Video: 03. Adding ObjectsAn Overview adding an object to an Alice Project

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

In this example, we click on Quadruped classes.

Select class folder

• 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.

Quadruped – walks on 4 legs

Click on the image to select one of 5 versions of objects that can be created by the DragonBaby class.

Select class

10 different versions of DragonBaby objects

• 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.

Select class

Enter a name for the new BabyDragon object

Adding a DragonBaby object to a Scene

• We have constructed a new instance of the BabyDragon class and identified it with the name fergie.

• We say an instance of a class is an object.

Instance/object

• 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.

Alternate technique

Objects of the same class

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

• Example: fergie and bert are two different objects (instances) of the same BabyDragon class. Different objects have different names and may have different colors, sizes, and other properties.