Creating a 3D Interactive Story
Prof. Susan Rodger
Duke University
Feb. 24, 2007
Now Create an Alice World
• Start Alice
• Select “File”, “New World”
• Click on Snow picture
• Click on “Open”
Find SnowPeople objects
• Click on “add objects”
• Scroll over to
“people” folder and
click on it
• Scroll over to
Snowman and
snowWoman
Add Snowman to World
• Click on snowman and you will see:
• Click on “Add instance”
• Snowman appears in world
Add SnowWoman to world and
adjust
• Click on SnowWoman and
add her to the world
• Click on arrow key
• Click and hold on snowman
to move him left and back
• Click and hold on
snowWoman and move her
to the right
• Scene should look like
Save World
• Save world
• Type in a name such as: snowPeople and
then “save”
• Alice will remind you to save your work
every 15 minutes
Now Ready to program!
• Click on done
• Should now see myFirstMethod
Write code to move the snowman
• This is the object tree, a list of
all your objects in the world
• Now click on the word
“snowman” to highlight it
• You should see methods below
it (things the snowman can do)
such as move, turn, roll, …
• Scroll down til you see “turn
to face”
Write code to move the snowman (2)
• Click left mouse button on “snowman turn
to face” AND HOLD IT DOWN, then Drag
it over and release the mouse button
• Click on “snowWoman”
• “the entire snowWoman”
Write code to move the snowman (3)
• Code appears
• Click on Play
Have the snowman talk
• Drag over “Snowman Say”
• Select “other” and type a greeting such as
“Hello there!
• Code is now:
• Play again
Now SnowWoman will act
• Click on snowWoman to see her
methods
• Drag over code and drop below
other code
• Play!
Now write a NEW snowman method
• Click on snowman
• Should see snowman’s
methods
• Click on “create new
method” and enter name
“getAttention”
• Empty method is created,
ready for you to enter
code
Write GetAttention Method
• Add the following code to this method
• Note you now have two methods:
• Click on myFirstMethod to get back to it
Add getAttention method to
program – to myFirstMethod
• Click on play
Repetition
• Sometimes you want to repeat
commands
• Let’s repeat “getAttention” three
times
• Click on “loop” and drag and drop at
the end of our code, below
getAttention
– Select “other” and type 3
– Click on left tab of “getAttention and
move it inside the loop
– Now Play!
Create snowman method - popHat
• Click on snowman in
objectTree
• select “create new method”
and name it popHat
Want the “topHat” part of snowman
• Click on + by snowman
• Click on + by head
• click on tophat to highlight it
Now we will move just the tophat
• Drag over the “move” command twice to
make the tophat move up and then down the
same amount
Make an Event
• We want the hat to move up
and down whenever we press
the “H” key
• Create a new event and select
“when a key is typed”
• Click on “any key” and select
the “letters” then “H”
• Click on “nothing” and select
“snowman” “popHat”
Making an Event happen
• Play your world
• Whenever you want the hat to pop up and
down, just press the key “H”
Add more code to myFirstMethod
• At the end of your code in myFirstMethod
– Add code to have the snowWoman turn toward
the snowman, say “I said hello” and turn back
• Remember to click on the word
snowWoman in the objectTree to get
snowWoman methods
Here is one possible way
Turn SnowWoman’s Head red
• In addition to methods, each object
also has properties you can drag and
change
• Select “SnowWoman’s Head in the
object tree
• Select the Properties tab
Turn SnowWoman’s Head Red (2)
• Click on color, hold and drag to right before
snowWoman says “I said hello”
• Select color “red” and release, results in:
At end, turn head back to “no color”
• Here are the two color statements added to
the code (note: “no color shows as white”)
• Play your world
Write a snowman Flip method
• Make sure you select “snowman” in the objectTree
• Create the method named “flip”
• Have the snowman do the following
– Move up 1 meter
– Roll left 2 revolutions
– Move down 1 meter
• Add code at the end of myFirstMethod
– Snowman says “Watch what I can do”
– SnowWoman turns to look at him
– Call the snowman flip method
• Play your world
Write a snowWoman flip method
• Make sure you select “snowWoman” in the
objectTree, then create the method “flip”
• Have the snowWoman do the following
– Move up 1 meter
– Drag up a DoTogether from the bottom
Write a snowWoman flip method (2)
• Inside the DoTogether you can put
commands that will happen at the same time
• Inside this DoTogether have the
snowWoman do the following:
– Turn forward 1 revolution
– Resize by half
• Below drop in another DoTogether with:
– Turn forward 1 revolution
– Resize by 2 (back to the right size)
• Add one more command to move
snowWoman down 1 meter
Now let’s call the SnowWoman
flip method
• Add code at the bottom of myFirstWorld
– SnowWoman should say “Watch what I can do”
– Call the snowWoman flip method
• Play your world
Here is what flip should look like
Add two new events
• Add an event so the snowman flips when M
is pressed
• Add an event so the snowWoman flips
when W is pressed
• Play the world, press M and W anytime
Add more objects to the world
• First let’s add two more
objects
• Click on “Add objects”,
find the “nature folder” and
add any tree to the world
• Click on it and push it far
back
• Find the “vehicles” folder
and find the scooter, add it
to the world (you may have
to look in the Web gallery
to find the scooter)
Adjust the scooter
• Click on the third
control and try
turning the scooter
around to face this
direction
• Then click on the first
control (the arrow)
and push the scooter
back between the tree
and the snowWoman
Write the SnowWoman method
driveAway
• First select the snowWoman in the
objectTree and create a new method named
“driveAway”
• Now let’s add code to this method
• First have the snowWoman turn to face the
backRightFloor (or may be called
RightFloor) part of the scooter
Move SnowWoman to the scooter
• It will be handy to test this method as we
build it, look at the event “When the world
starts”
• Click on the white arrow and select
“snowWoman.driveAway”
• Now when the world starts, only this
method will play – Click Play and see
Write snowWoman driveAway (2)
• We want the snowWoman to move to the
scooter.backRightFloor, but we don’t know
how far it is
• Have the snowWoman move forward 1
meter and Play it
• It’s not quite far enough
Write snowWoman driveAway (3)
• We can use a snowWoman function to drop in the
distance to the scooter.backRightFloor
• Click on SnowWoman functions
• Drag “distance to” and drop on “1 meter” when it
turns green, then select “scooter.backRightFloor”
Write snowWoman driveAway (4)
• Play the world
• It is hard to tell, but she goes right into the
scooter.
• We’d like her to stop in front of the scooter.
• Click on the last arrow and select “math”,
then “minus” then “0.5”
• Now she stops 0.5 meters in front of it
Write snowWoman driveAway (5)
• Next, have the snowWoman doTogether
– move up 0.2 meters
– Move forward 0.5 meters
• We’d like the scooter to move and have the
snowWoman move with it
• We can set the vehicle property of the
snowWoman to be the scooter
Write snowWoman driveAway (6)
• Click on snowWoman’s properties
• Drag over “vehicle” and select “scooter”
Write snowWoman driveAway (7)
• Almost done, add a few more commands
• In a DoTogether
– The snowWoman says “Bye”
– The scooter moves forward 10 meters
– The snowman’s head turns ¼ turn to the left
(make sure you select snowman in the objectTree)
• One more command after the DoTogether
– Snowman’s head turns back ¼ turn to the right
snowWoman driveAway – final code
Call snowWoman driveAway
• Back in myFirstMethod, add a call at the
end of your code to call the method
snowWoman.driveAway
• Fix the first event so that when the world
starts, world.myFirstMethod is called
• Play
Write a snowman melt method
• Add a snowman method named “melt”
• The code should repeat 12 times
– Move the snowman down a little (0.1 meters)
– Wait 0.5 seconds (drag the “wait” tile up from
the bottom)
• At the end of myFirstMethod, call melt
• Play the world
Almost Done – add title
• Click on “add objects”
and go to the right end
of the local gallery and
find 3D text
• Click on it and add a
short title such as “Life
as SnowPeople”
• You’ll have to use the
control keys to move it
up, back, and turn it to
face the right way (use
first three controls)
Title only in the beginning
• Notice the title is an object in the
objectTree - Click on it
• We would like it to disappear after
the snowman says “hello there”
• Drag over the “isShowing”
property and set it to false
Add “The End”
• Add another 3D text that says “The End” and
position it over the title
• Click on THE END in the objectTree
• In properties, click on “true” of “isShowing”
and select “false” – The End will disappear
Make “The End” Reappear
• Make “The End” visible before the
snowman melts
You are now done!
• Play your world!
• You can download Alice for free at
www.alice.org
• My web page
www.cs.duke.edu/~rodger