Introduction to Alice. Alice is named in honor of Lewis Carroll s Alice in Wonderland

Transcription

1 Introduction to Alice Alice is named in honor of Lewis Carroll s Alice in Wonderland

2 Computer Programming Step by step set of instructions telling a computer how to perform a specific task 2 problems some people have with Computer Programming Language C++, JAVA, Visual Basic Visualization

3 A Computer Program Has the Following:

4 A list of Instructions: Sequential Processing - Recipe Ifs: Conditional Execution If you have a test, take your book home Repeating Behavior: Looping or iteration Clap 4 times, or WHILE there are cookies on the plate, keep eating

5 Breaking things up into Smaller Pieces: Decomposition, Stepwise Refinement, top-down design - Take a large task and break it down. We are going to make dinner. First peels the potatoes, then de-bone the chicken, etc. Compute a Result: Calling a function Asking a question??? Perform a series of steps to obtain a result. What is John s phone #?

6 Planning out your Program Sketch your design on paper Storyboard Flowcharting basic collection of symbols

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8 (1) Fill the bath with water (2) Get undressed. (3) Get into bath. (4) Wash. (5) Get out of bath. (6) Empty the bath water. (7) Get dressed. Flow Chart Example 1 We will now draw a flow chart for having a bath. We start by thinking about the steps involved: Now we need to draw the chart with instruction Boxes. There are no decisions on this chart - the steps all follow on from one another. Remember the Start and End boxes. Of course some people might do some of these steps in a different order, but hopefully they get undressed before getting in the bath!

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10 Flow Chart Example 2 We will now draw a flow chart for having a bath. We start by thinking about the steps involved: The step Fill the bath with water in the previous example could have been more detailed. For example, you need to check if there is enough water and whether it is at the right temperature while running the bath. Again we need to think about the steps involved: (1) Turn on the hot and cold taps. (2) Is it too hot or cold? If it is, go to step 3, otherwise go to step 4. (3) Adjust the hot and cold taps and go back to step 2. (4) Wait for 2 minutes. (5) Is the bath full? If it is, go to step 7, otherwise go to step 6. (6) Go back to step 4. (7) Turn off the hot and cold taps. Now we need to draw the chart. This time we need to use decision boxes for steps 2 (where the temperature of the water is checked) and 5 (where it is checked if the bath is full).

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12 Alice Object-Oriented Programming 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)

13 Kinds of Animations Two kinds of animations: Movie Passive user watches the animation Interactive Active user clicks on mouse, types a key on keyboard Actions of user are called events

14 Object Tree World View Events Editor Events Panel Editor

15 Camera Navigation - is used to set the camera point of view Move moves camera left, right, up and down Tilt Camera up or down, like tilting your head up and down Zoom & Pan Zoom in & out and pan left & right

16 Quad View - position one object relative to another object See Handout The default setting is to move the entire object. AFFECT SUBPARTS you can move PARTS of the OBJECT

17 Objects An "object" is any thing that can be identified as unique from other things How is an object unique? has a name has properties: width, height, depth, color, location can perform actions (methods): associated actions it can perform (movie) tasks it can carry out (interactive)

18 Object Parts (Object Tree) Objects may be composed of parts

19 3 Dimensions, 6 Directions A 3D object has 3 dimensions height, width, depth 6 degrees of freedom (directions of movement)

20 Center of an object At the center of mass Where it stands on the ground Where it is held

21 Galleries Classes (3D models) are found in the galleries Local gallery (installed with the software) Minimum or complete options CD Gallery (only if CD is in the machine) Web gallery

22 Demo: Saving a world 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 or memory key)

23 Assignment Read (before the next class session) Chapter 1 Section 1, Introduction to Alice Section 2, Alice Concepts Tips & Techniques 1, Special Effects