1. LCC 6310 Computation as an Expressive Medium
Lecture 1

2. Overview Go over the syllabus Brief introduction to me and my work
Art, programming and Java

3. Syllabus

4. Background Ph.D. in Computer Science
Expressive AI: Artificial Intelligence-based art and entertainment
Worked in industrial research labs (Intel, Tektronix) doing HCI research
New at Georgia Tech – arrived in January

5. AI & Art The Senster, 1970 Black and White, 2000 Edward Ihnatowicz
Peter Molyneux (Lionhead)

6. Work Façade – interactive drama Terminal Time – interactive video
Illustrate these ideas by describing three AI-based artworks.
I’ll talk briefly about Office Plant #1, and in more depth about Terminal Time and Façade.
This talk is primarily structured as a computer science talk – if you are more interested in conceptual, aesthetic, or art theoretic issues, please ask at the end.
Terminal Time – interactive video
Office Plant #1 – robotic sculpture

7. Façade
Dramatic world inhabited by computer controlled characters (believable agents)
The user (player) plays a protagonist within the story, first-person point of view
The player experiences a story with a dramatic arc
Collaborator:
Andrew Stern, independent artist and researcher

8. Terminal Time Collaborators:
Goal trees (ideology)
Historical events
Audience feedback
Audio-visual
elements
Collaborators:
Steffi Domike, Design Department, Chatham College
Paul Vanouse, Art Department, SUNY Buffalo

9. Office Plant #1 Creates a background presence
Sorts incoming into social and emotional categories
Behavior is a function of the received
Switch to video at the end of this slide.
Collaborator:
Marc Bohlen, Media Studies, SUNY Buffalo

10. Combine AI research and art
Expressive AI
Artistic practice
AI research
Wrestling with meaningful human experiences suggests new AI research directions…
AI methods and technology suggest new audience experiences…

11. Some directions I’m someone to chat with about…
Interactive story (particularly procedural approaches)
Robotic sculpture
Video games as a cultural practice (design and technology)
Meta-art (generative systems)

12. Introduce yourselves

13. Programming languages
Abstract, “human understandable” language for telling computer what to do
The abstract language must be translated into the low level language understood by the machine
This translation is accomplished by an interpreter or compiler
We will be learning the compiled language Java

14. A simple Java program Human readable?!? class PrintLoop {
public static void main(String[] args) {
for (int i = 0; i < 10; i++)
System.out.println("i = " + i); }
Just prints the numbers 0 to 9 on the screen

15. “Human readable” is relative
class PrintLoop {
public static void main(String[] args) {
for (int i = 0; i < 10; i++)
System.out.println("i = " + i); }
Java compiler translates this into…

16. Java VM assembly code public static void main(java.lang.String[]);
0: iconst_0
1: istore_1
2: goto 30
5: getstatic
8: new
11: dup
12: ldc
14: invokespecial #23
17: iload_1
18: invokevirtual #27
21: invokevirtual #31
24: invokevirtual #34
27: iinc 1, 1
30: iload_1
31: bipush 10
33: if_icmplt 5
36: return
test.PrintLoop();
Code:
0: aload_0
1: invokespecial #43;
4: return

17. Object Oriented vs. Procedural Languages
Procedural (e.g. C)
We create some data representing an image (array of pixels to draw on the screen)
We write a procedure than can be passed the image and will draw it
Object Oriented (e.g. Java)
We create a class that contains an image AND a routine draw it
The data and the behavior (ability to draw) are in one "container"

18. A couple of Java’s relatives
Smalltalk 80
Alan Kay and the Dynabook (PARC)
C++
Managing big C programs: Bjarne Stroustrup

19. Smalltalk 80 Alan Kay and the Dynabook (PARC)
Developed idea of a general purpose computer to be used by normal people!
Highly interactive interface
Included concept of windows!
Smalltalk 80 – end users could create their own tools

20. Smalltalk 80 Includes objects Objects contain data and procedures
Procedures in objects are called methods
All computing is done by sending a message to an object asking it to perform one of its method
Objects are defined by classes

21. C++ Managing big C programs: Bjarne Stroustrup
Started as "C with Classes" idea borrowed from Simula 67 & Smalltalk
Goals
Organize programs as classes with inheritance
No performance penalty compared to C
Thus somewhat dangerous!!!
C++ is converted into C

22. Java Designers started with C++ Programming embedded systems
Smaller
Simpler
Safer
Programming embedded systems
Toasters, microwave ovens, TV set top boxes
Reliability very important--avoid costly recalls
Web programming
Incorporated into web browsers at critical moment

23. The virtual machine
Since Java was designed to run on embedded systems, it was designed around a virtual machine
“Write once, run everywhere” PC
Mac
Cell Phone
Java VM
Java VM
Java VM
Windows
OS X
Phone OS
x86
G3/4/5
Processor
Java Machine
“Java OS”
Java VM

24. Steps for running a Java program
“Source
Code”
HelloWorld.java
Java
compiler
javac HelloWorld.java
Generic
“Byte
Code”
HelloWorld.class
OS-specific JVM
java HelloWorld
Execute
program
OS-specific
“Object
Code”

25. Structure of Java programs
Create one or more Java source files
Compile each source file into a class file
An application consists of these class files (not a single file like a .exe)
To run the program, send one of the class files to Java
This entry file must have method called main
public static void main(String[ ] argv)

26. Sample application File: HelloWorld.java public class HelloWorld {
public void greet() {
System.out.println("Hello World!"); }
public static void main(String argv[]) {
HelloWorld hw = new HelloWorld();
hw.greet();

27. Java file and class names
Source code files must have the ".java" extension.
The file name should match the class name. The class name should start with a capital letter. This naming convention is enforced by most reasonable compilers.
A file containing
class HelloWorld {…}
must be named HelloWorld.java
Compiled bytecode has the ".class" extension

28. Compiling HelloWorld HelloWorld.java HelloWorld.class javac
public class HelloWorld {
public void greet() {
System.out.println("Hello World!"); }
public static void main(String argv[]){
HelloWorld hw = new HelloWorld();
hw.greet();
HelloWorld.class
javac
javac HelloWorld.java
0xCAFEBABE ...
javac is the Java
Compiler

29. Executing HelloWorld HelloWorld.class java HelloWorld java is the Java
0xCAFEBABE ...
java HelloWorld
java is the Java
Virtual Machine
C>java HelloWorld
Hello World!
C>

30. Object Oriented Programming
OOP is all about programming using something called an object.
Objects are created from classes. An object is called an instance of a class.
Objects do useful stuff by calling methods on them.
Let’s look at classes and objects in more detail.

31. Previously... public class HelloWorld { public void greet() {
System.out.println("Hello World!"); }
public static void main(String argv[]) {
HelloWorld hw = new HelloWorld();
hw.greet();

32. A Class class Greeter { String greeting;
A class will be used
to define how objects
made from this class
will operate
class Greeter {
String greeting;
public Greeter(String newGreeting) {
greeting = newGreeting; }
public void greet(String name) {
System.out.println(greeting + ", " + name);

33. Field class Greeter { String greeting;
A class typically will
have one or more fields
which are the data items
which the object holds
class Greeter {
String greeting;
public Greeter(String newGreeting) {
greeting = newGreeting; }
public void greet(String name) {
System.out.println(greeting + ", " + name);

34. A Constructor class Greeter { String greeting;
Classes can have Constructors
which contain code only run
when an object is created.
Useful for initialization
class Greeter {
String greeting;
public Greeter(String newGreeting) {
greeting = newGreeting; }
public void greet(String name) {
System.out.println(greeting + ", " + name);

35. A Method class Greeter { String greeting;
Once created an object can be
asked to run a "method" which
will do something normally
involving data stored by the object
(plus sometimes data passed in.)
class Greeter {
String greeting;
public Greeter(String newGreeting) {
greeting = newGreeting; }
public void greet(String name) {
System.out.println(greeting + ", " + name);

36. Another Class This class is just being used to hold
a main method. Here we make two
Greeter objects and use them
class Driver {
public static void main(String args[]) {
Greeter g1 = new Greeter("Hello");
Greeter g2;
g2 = new Greeter("Good morning");
g1.greet("Bob");
g2.greet("Mary");
g1.greet("Sam");
g2.greet("Joan"); }
C>java Driver
Hello, Bob
Good morning, Mary
Hello, Sam
Good morning, Joan
C>

37. OOP
OOP consists of designing a bunch of classes most of which are used as templates to make objects
The objects are used to hold data
They are initialized with constructors and perform useful functions by being asked to run their methods