1. Setting Up the Initial Scene

2. Problem Solving in Alice
Read and understand a scenario – tell a story, play a game, carry out a task.
A princess has been grounded by her father (a wizard) and kept inside the castle. Being a rather rebellious princess, she has ed the local dragon taxi service. The dragon will fly to the princess and she will climb aboard the dragon to escape from the castle – to meet some friends at the village dance club.

3. Problem Solving in Alice
Set up the initial scene in a new world
The princess example
Setting up the initial scene

4. Select Template

5. Add Objects Click on Add Objects button
Toggles from code editor to scene editor

6. Scene Editor Add objects to the world Two options
Drag and drop
Click on thumbnail; then click on Add Instance button
Add dragon from Web gallery’s Medieval collection

7. Position & Orientation
Objects
are positioned in 3-D space
have a sense of orientation
have six degrees of freedom (directions of movement)

8. Mouse Control Toolkit
To reposition objects in the world, use the buttons in the mouse control toolkit

9. Starting the initial scene
Open the PrincessAndDragon world (Hdrive)
Do Save World As and save the file on your p-drive or on a flash drive
Add the dragon and position it in the scene
Add the princess and position her in the scene hint how to do that further

10. Pull-down menu methods
Alternative technique for positioning object and subparts during scene setup.

11. Quad View – Relative Positioning

12. Empty quad view pane?
Scroll & Zoom controls can be used (usually) to reorient the camera view.

13. Save the world
This is a world that we will use in a few lessons.

14. Motion Motion of an object is relative to
the orientation of the object
the center of the object

15. Orientation Orientation is an object’s sense of direction
A 3D object has
3 dimensions
height, width, depth
6 directions of motion

16. Center of an object
An object is positioned in the world, with reference to the center of the object.
The center of an object can be:
At the center of mass, or
Where it stands on the ground, or
Where it is held or connected (for example, a hinge joint)

17. Bounding Box
Viewing the intersection of axes in an object’s bounding box is one way to determine where the center of an object is located.
Mac users:
Bounding boxes work only in Alice 2.2. We will look at an alternate way of finding an object’s center in later slides.

18. Demo & Practice Create a new world Where is the center of each object?
tortoise (Animals gallery)
evilNinja (People gallery)
Where is the center of each object?
What is the forward direction of each?
What is the up direction of each?
Goal 1: Participants illustrate an understanding of orientation as being egocentric
for each individual object.
Activity 1:
Position the tortoise and the evilNinja on the ground and resize as needed so that the tortoise and the evilNinja appear to be “facing one another”
Ask questions (see the slide) about the tortoise and the airplane.
Center: evilNinja – between the feet; tortoise - center of mass
Forward: evilNinja – toward the tortoise; tortoise – toward the evilNinja
Up: evilNinja – through the head; tortoise - through the head
Goal 2: Participants illustrate an understanding that the orientation of an object can be changed to be the same as the orientation of another object.
Activity 2:
Reposition the tortoise and evilNinja so they appear to be standing side by side, facing in the same direction.
Ask the same questions again.

19. Translational Motion Change of position of a whole object in the world
The direction of translational motion is stated relative to the orientation of the object.
Six possible directions
move
left
right up
down
forward
backward

20. Set-up methods
To illustrate object motion, we will use the scene editor’s popup menu of set-up methods.
Demo of using a set-up method:
Add a 3D axes object to the world with the tortoise and evilNinja
Right-click on the 3D axes object
Select “methods” from the menu
Select a method

21. Selecting set-up method: orient to

22. Demo & Practice Use a set-up move instruction with Note: tortoise
evilNinja
Note:
You can click the Undo button to return an object to its initial position before trying another move.

23. Question
Other than move, what other methods in the set-up popup menu can be used for “translational motion”?
Answers include: move to, move toward, move away from, set point of view to, move at speed

24. Rotational Motion: Entire Object
Rotational motion changes the orientation of an object in the world
An object’s center acts as its pivot point for rotation of the whole object.
Two forms of rotational motion:
turn
forward, backward
left, right
roll

25. Hands-On Practice Add a biplane (Vehicles gallery) to the world
Use turn and roll set-up methods with the whole biplane
Note:
Be sure to click the Undo button to return to initial position before trying another rotational motion.
Note how the movement is around the biplane’s center (which is within the body of the biplane)

26. Question
Other than turn and roll, what other methods in the set-up method menu can cause “rotational motion”?
Answers include: orient to, point at, turn to face, stand up, turn at speed, roll at speed

27. Rotational Motion: Subpart
Rotational motion of a subpart of an object may have a surprising result
Turn and roll actions for a subpart are pivoted around the center of the subpart, generally located where the subpart connects to the rest of the object
(see example, next slide)

28. Example
The tortoise’s right arm is centered at the base (the connecting joint) of the upper arm to the body
Note: A few Alice 2 models were designed to work differently and, therefore, do not conform to this standard structure.

29. Center for a subpart
One way to view the center of a subpart is to move an axes object to the subpart and then orient the axes to the subpart.
Example: tortoise rightArm’s center