1. Dimensions and Directions
Introduction to Alice
Dimensions and Directions

2. Introduction to Alice – Dimensions and Directions
Alice is a 3 dimensional (3D) virtual world made of objects controlled by the programmer
Many of these objects are already built for you
Hundreds in the galleries on Alice
Thousands more available online
You can create objects as well

3. Introduction to Alice – Dimensions and Directions
Each object is defined in 3 dimensions
HEIGHT
WIDTH
DEPTH
Each measurement is RELATIVE TO THE OBJECT ITSELF
If the chicken is on its back, its height is still measuring from its head to its feet
WIDTH
DEPTH
HEIGHT

4. Introduction to Alice – Dimensions and Directions
Each object has 6 possible directions it can travel UP
Down
FORWARD
Backward
RIGHT
Left
Each measurement is RELATIVE TO THE OBJECT ITSELF
When you select the object, a box shows up around it with 3 lines

5. Introduction to Alice – Dimensions and Directions
CENTER
The center of the object is where these 3 lines meet
Usually in the center of mass (geometric center)
the center is sometimes at its base (buildings, people)
Sometimes it is where the object is held
CENTER (inside car)

6. Introduction to Alice – Dimensions and Directions
POSITION
Every object in Alice has a center
Even the ground has a center, which is the center of the world. 
Every object's position is measured relative to the center of the world.
For any object (including the ground), select the object and look in the Properties panel/tab.  There will be a set of three co-ordinates relative to the center of the world (0,0,0).
DISTANCE
Distances between objects are measured along straight lines between centers
*Not all objects will have their centers on the ground, so don't assume that their distance will be along the ground either*