CS320n – Elements of Visual Programming Introduction to Alice Mike Scott (Slides 1-1)

Visual ProgrammingIntroduction to Alice2 What We Will Do Today look at the Alice programming environment create some simple programs in Alice

Visual ProgrammingIntroduction to Alice3 What is Alice? Named in honor of Lewis Carroll’s (pen name) Alice in Wonderland –Charles Lutwidge Dodgson was also a mathematician and logician A modern programming tool –purpose of tool, learn how to program, write algorithms –3-D graphics –3-D models of objects Animation –Objects can be made to move around virtual world (a simulation or a video game. Simple Pixar.) Pixar

Visual ProgrammingIntroduction to Alice4 Computer Programs General purpose programming languages can be used for almost any task Alice is not a general purpose programming language. –It is an application specific language –designed for a specific task, creating 3D animations –lots of application specific languages. Example: language for working with DNA data

Visual ProgrammingIntroduction to Alice5 Fundamental Tools All languages contain these elements 1.list of instructions – “Pack lunch, pack snack, put homework in backpack.” 2.decision making – “If I didn’t shave yesterday, shave today.” 3.repetition of behavior – “Do a load of laundry until there is no more dirty laundry.” 4.modularization. Big rocks into little rocks. “To do a load of laundry: gather clothes, get clothes right- side out, put clothes of similar color into washing machine…” 5.Generalization: Solve many different problems with one set of instructions 6.Compute a result – “How much is it going to cost to fill up my car with gas?”

Visual ProgrammingIntroduction to Alice6 What does Alice run on? Alice is free. Alice is written in Java –only working versions are for PCs and Macs with OSX 10.3 or higher (relatively new, may still have bugs) –Sorry, no Linux, yet –the book comes with a copy of Alice for Windows machines – –also on the computers in the CS Elements lab

Visual ProgrammingIntroduction to Alice7 Fast Start Up Can quickly learn to create –a simple animation in a matter of minutes –a non-trivial animation in a few class periods Can learn to use the Alice interface in a few class periods if you do a couple of exercises at home

Visual ProgrammingIntroduction to Alice8 Installing Alice If you want to install Alice on you computer at home –use the CD that comes with the textbook CD installation is straightforward –download Alice from the web file format is.zip must “unzip” file using a program such as winzip problems? post to newsgroup

Visual ProgrammingIntroduction to Alice9 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: Alice (the program) reminds you every so often so save your work save your programs often! if working in lab when you logout the computer is wiped -> save to your account or to a backup system such as a memory stick

Visual ProgrammingIntroduction to Alice10 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

Visual ProgrammingIntroduction to Alice11 Demo Starting Alice Loading a World Running A World Saving a World How to Exit

Visual ProgrammingIntroduction to Alice12 The World Alice Programs / Movies take place in a virtual world When you start a new world in Alice you select the background The world consists of a sky and the ground Can’t be changed after creating the world the world is not infinite DEMO (I don’t like roller coasters any more)

Visual ProgrammingIntroduction to Alice13 Objects in Alice Objects already exist. Hundreds of them

Visual ProgrammingIntroduction to Alice14 Program an Object

Visual ProgrammingIntroduction to Alice15 Where Do Objects Come From? They are pre built –creating 3D objects is another area of computing and graphic design Sources of 3D objects – the local gallery that comes with the software – Alice web gallery How are objects added to the world?

Visual ProgrammingIntroduction to Alice16 Adding Objects Click on the green “Add Objects” button World expands and local gallery displayed

Visual ProgrammingIntroduction to Alice17 Adding Objects Local gallery divided into a directory based on subject add instances of objects to world by –dragging and dropping or –click on object and select add instance option

Visual ProgrammingIntroduction to Alice18 Objects in the World Can have multiple instances of objects from the same class in the World –class: like a cookie cutter –objects: like the cookies star cookie cutter star cookie class star cookies star cookie objects

Visual ProgrammingIntroduction to Alice19 Objects in the World penguin classpenguin objects in a virtual world

Visual ProgrammingIntroduction to Alice20 Objects in the World The Objects that are present in the current world are listed in the Object Tree The top left panel in the Alice programming environment Every world comes with a light, a camera (point of view for the movie when played), and the ground

Visual ProgrammingIntroduction to Alice21 Object Dimensions Objects in Alice worlds are 3 dimensional height width depth

Visual ProgrammingIntroduction to Alice22 Object Position Objects – are positioned in 3-D space – Have six degrees of freedom (directions of movement)

Visual ProgrammingIntroduction to Alice23 Objects “Know” Relative Directions Yellow box around penguin is its bounding box light blue line is up/down pink line is left/right dark blue line is forward backward DEMO

Visual ProgrammingIntroduction to Alice24 Exercises if you want to work at home, install Alice on your computer Complete Appendix A, Part 1, using Alice –a walkthrough of using Alice Complete the tutorials that come with Alice

Visual ProgrammingIntroduction to Alice25 Starting Tutorials