3D Animation for the Raw Beginner Using Maya

93

Chapter 4

Hierarchies of Objects, a Polygon

Example, Detailed Polygon

Modeling, and a NURBS Example

I

  , we will continue to look at modeling. We take the approach of incre-

mentally digging more deeply into both polygon and NURBS modeling. Our goal is to

become comfortable with both, with a bit of a bias toward polygon modeling, as it is a core

3D technique with which every 3D artist needs to be familiar.

We rst examine a few semiformal and conceptual issues in Maya, then we build a

polygon model, take a high-level look at the process of creating another polygon model,

and study some techniques for performing various detailed polygon modeling tasks. And

nally, we look at constructing a NURBS model.

BASIC CONCEPTS

Modeling Hierarchies

We have been informally using the word model to refer to the goal of the 3D modeling

process. Of course, one must have a specic end point in mind. Although any complex

model (and many simple ones) will evolve during the process of creating it, you don’t want

to be making incidental models by continuing to semirandomly massage an object until it

nally looks like something interesting.

Perhaps a more critical notion is what gives a model its identity in the eyes of the mod-

eler. e quick answer is that it is at the root of an object hierarchy.

Objects

First, remember that the word object has a specic meaning inside Maya, and it refers to an

item stored in the Maya database. Objects can be things that are directly rendered or they

94 ◾ 3D Animation for the Raw Beginner Using Maya

can be abstract. In either case, they have attributes. Maya does, however, hide the specics

of its data management from us, and so it’s actually dicult to know precisely what is an

object and what is not.

We have also used the term object in a somewhat informal way to refer to pieces of a

model or early stages of a model.

Either way, models are made up of objects.

A model might be made of other models, as well. A model of a house might have smoke

coming out of the chimney, and that smoke eect might be a model that was made earlier

and then imported into the scene containing the house by going to File on the Main Menu

and selecting Import.

Formal Notions

e word model does not have a precise meaning in Maya, although we will continue to say

that a model is made of objects arranged in a hierarchy.

ere is a formal notion in Maya, though, of a project, as each project is a specic folder

in the Maya le directory. In this book, when we talk about scenes we will usually be refer-

ring to a specic .mb or .ma le within a Maya scenes folder, which is within the Projects

folder. So a scene is also a formal notion.

Maya binary les are encoded as bit les. Maya ASCII les consist of code. As an experi-

ment, you might try storing a scene as an ASCII le, and then look at the vast amount of

code that must be generated to create even

a simple model. is will give you a sense

of the astonishing amount of computational

power hidden inside Maya.

A .ma or a .mb le can be imported into

an open scene, and so our smoke eect

might be stored as its own .ma or .mb le.

We might reasonably conclude that a

scene is a precise thing that contains one or

more models, and that a model is made up

of objects.

Hierarchies

Remember the cactus we made from

NURBS curves. In Figure4.1, we choose:

any Main Menu → Window → Outliner

is window allows us to take various

objects in a scene, give them names, and

put them in a hierarchy. You can also give

objects names by using the Attribute Editor.

And of course, it is always a good idea to give

the objects in your scene meaningful names.

FIGURE 4.1 e Outliner.