Cool Concepts ◾ 411
Cool Concept 2: What is a model?
Within Maya, there is a semiformal notion of an object—It can be something that will
render, like a car windshield, or something that does not directly render, like a path along
Models are in the eye of the animator. Often, the root of an object hierarchy is what the
animator considers to be a model.
World Space (x, y, z):
Its center is at (0, 0, 0) of the scene
Object Space (x, y, z):
a given object. Its center is at
Local Space (x, y, z):
Each object in the hierarchy
inherits the Object Space of its
parent (as its Local Space). In this
way, a complex object will move as
a coherent whole.
Surface Texture Space (u, v):
the surface of a given object.
Cool Concept 1: Object hierarchies and multiple (x, y, z) spaces
One of the most critical things a 3D animator must do is carefully place all objects in
appropriate hierarchical relationships with other objects. is allows the motion of one
object to depend on another object. is is how an object can be moved independently
but also be certain to move with respect to its parent. Building hierarchies also provides a
convenient way to place diﬀerent materials on diﬀerent parts of an object.
▾ A Closer Look: Examples of using multiple (x, y, z) spaces
Consider a car on a roadway with various Objects hierarchically arranged.
Each axle has its own Object Space; its Local Space is the Object Space of the body of the car.
Now, the wheels turn independently, but they stay on the axle as the car moves forward. When a sinkhole
creating hierarchical movement. If we make the windshield of the car a child of the body of the car, it will
be easier to give the windshield its own material. It will also make it easier to reuse that windshield on
opens under the road, the road falls and the car follows, and the axles and the wheels go with it. e wheels
are still spinning.