Introduction to Alice

1
Introduction to Alice

Alice is named in honor of Lewis
Carrolls Alice in Wonderland
2
How This Class Will Work

• General plan
• lecture/demonstrations
• tutorials
• lab exercises
• Out-of-class
• complete any work not finished in lab
• work on assigned readings and projects

3
Overview

• Why Alice?
• Getting Started with Alice
• Where to find software and 3D models
• Major goal set up and run Alice
• Animations in Alice
• Classes and Objects in Alice
• Objects have parts

4
How To Get Your Free Copy

• Can download from the web
• www.alice.org
• Note downloading may take more than an hour
  over a phone/modem connection

5
Why Alice?

• A modern programming tool
• 3-D graphics
• 3-D models of objects
• Animation
• Objects can be made to move around the virtual
  world (a video game or simulation implemented in
  3-D)

6
What does Alice run on?

• Alice is written in Java -- this helps the
  software run on many popular systems
• Right now, the software team is working to
  support only the PC version
• Mac and Linux versions are soon to be released
• keep checking the web site

7
Fast Start Up

• Can quickly learn to create
• a simple animation in a matter of minutes
• a non-trivial animation in a few lab sessions
• Can learn to use the Alice interface in a couple
  of lab sessions

8
The Power of Alice

• Automatically keeps track of 3-D objects
• what objects are in the virtual world
• types of objects
• positions of objects in the world

9
Demo

• Starting Alice
• Running A World
• How to Exit
• What to do if Alice crashes

10
Memory Management

• Alice automatically manages memory
• But, writing and testing an animation is an
  intense load on the computing system a crash
  can occur.
• Best solution
• save your world every 15 minutes
• (Or at least every half hour)
• also save to a backup system
• (for example, a zip disk)

11
Kinds of Animations

• The animation just viewed was a "movie"
• Two kinds of animations
• Movie
• user watches the animation
• "machine-centric"
• Interactive
• user clicks on mouse, types a key on
• keyboard
• "user-centric"

12
Events

• Animations that are interactive depend on the
  user's actions
• mouse click
• key press
• others (HeadMountedDevice, etc.)
• Actions are events
• Interactive programs are event-driven

13
Interactivity in Alice

• Demo of interactive program in Alice
• What are the events?
• What response does the skater make to each event?

14
Objects

• In the demo worlds, the octopus and skater are
  objects.
• An "object" is
• anything that can be identified as unique from
  other things
• How is an object identified as unique?
• has a name
• has properties
• width, height, color, location, age, ss, id
• has a purpose
• associated actions it can perform
• tasks it can carry out

15
Class

• Objects are categorized into classes
• Each object is
• an instance of the class.
• All objects in a class have similar properties
  and generally can perform the same tasks.

16
Objects in a Virtual World

• In Alice, each 3D model is a class of objects
• each object of the class has a unique name
• mummy, mummy1, mummy2
• has color(s)
• pink, white, grey, black, blue, .

17
Galleries of 3D Objects

• Sources of 3D objects
• the local gallery shipped with the software
• Alice web gallery

18
Object Parts

• Objects may be composed of parts

19
3D objects

• A 3D object has
• 3 dimensions
• height, width, depth
• 6 degrees of freedom (directions of movement)

20
Center

• At the center of mass
• Where it stands on the ground
• Where it is held

21
Assignment

• Your assignment is to read
• Chapter 11, Introduction to Alice
• Chapter 1-2, Alice Concepts
• Tips Techniques 1, Special Effects
• The reading assignment is to be
• completed before the next
• class session

22
Lab

• Appendix A, Getting Started Parts I II
• Exercises from Chapter 1
• Notes
• Lab exercises and projects require that you
  demonstrate the code and execution of your
  programs to the instructor or the TA
• Your lab sheet must have the signature of
• the instructor or TA for each assigned
  exercise and/or project. Otherwise, you
  will not get credit for having completed
  the lab!