45
Chapter 3
Modeling, Creating
Materials, and Rendering
W
a high level look at modeling, focusing on some suggestions for
how to get organized as you begin the process. en we will look at a few modeling
examples in detail. Along the way, we will take our rst look at putting materials on models
and rendering them. We start with the task of building 3D models.
MODELING AS A SUBJECTIVE PROCESS
ere is no single method by which you should model. ere are almost always many ways
of obtaining a desired result. And, since Maya is a vast application that was built incre-
mentally over a number of years (and is still being built), it has many idiosyncrasies that
animators have learned to live with, and in fact, have found creative ways of exploiting. As
you gain experience and condence, you will develop your own style—and oen the most
astonishing models are made in some unorthodox ways.
So everything that follows is only meant as a possible way to proceed when you cre-
ate your rst models. I would suggest that you start with human-made objects in the real
world, things that are naturally angular, and as a result, are easily modeled with polygon
modeling. ere is nothing you cannot build with polygon modeling, although some ani-
mators prefer to use subdivision or NURBS when making smooth, organic objects.
First, we will consider some basic modeling guidelines, and then we will look at exam-
ples that will help make the overall process tangible.
Deliberate Modeling
A common mistake made by novice animators is to create “accidental models.” is is
what happens if you don’t model with step-by-step discipline, craing your models care-
fully. e result is oen a model that seems random and inelegant. If it was meant to model
something that appears in the real world, it is obviously awed. If it was meant to capture
an otherworldly vision in the mind of the modeler, that vision seems muddled. A common
46 ◾ 3D Animation for the Raw Beginner Using Maya
symptom is surface geometry that seems unnecessarily noisy and that does not seem to
have any functional or artistic purpose.
e way to avoid this is to plan and to have a specic modeling vision in mind. at
means you need to choose your type of geometry carefully. You might think that you could
begin a given model with either a polygon or NURBS sphere. But the surface geometries
of these two starting points are extremely dierent, and the tools available in Maya vary
dramatically in their nature and eect. at initial decision has to be made with a model-
ing plan in mind.
Models and Objects
Maya’s notion of an object is broad. Everything in your scene is an object or made from
objects, including lights and materials. Let’s focus on objects that appear in a scene and
have 2D (like planes) or 3D geometry. Models that we build in Maya are typically made up
of such independent pieces of geometry.
Try the following:
any Main Menu → Create → Polygon Primitives → Sphere
and use this tool to create a sphere by clicking and dragging.
Now try the following:
RMB (right mouse button) hold → (Edge|Vertex|Face|Object)
Choosing Object means that we are going to manipulate the entire sphere. If we choose
Edge, Vertex, or Face, we will go into modes that let us select specic pieces of that sphere.
But note that there is no “model” mode. What makes up a model is a creative decision,
one that exists only in the mind of the animator. Models in Maya are made up of objects
that are usually arranged into a hierarchy, and the choices you make when deciding what
object is the parent of what other objects are fundamental to your scene.
You will nd that polygon modeling lends itself to a natural component-based
approach to building models, with clearly dened, hierarchical internal boundaries
between objects that form a given model, and this is a key reason why polygon modeling
remains a favorite.
Top-Down Modeling
You should not take on a scene that will have models that are too complicated or too
numerous for you to nish in an elegant, complete fashion. So instead of trying to create
an entire house, you may want to build a living room. And remember to draw your scene
out by hand or with a vector drawing program rst.
A good thing to do if you are a beginner is to rough out your model rst and then to
model in a top-down fashion. Usually, it’s best to break the scene into individual models
that represent real items in the world. Each model should be formed from the object com-
ponents that the item has in the real world. So, we start with the room itself, a cube, per-
haps with one wall missing, to create a sort of stage on which to build the scene. at cube
should be carefully scaled to the proportions envisioned for the room.
Modeling, Creating Materials, and Rendering ◾ 47
Models can contain other models. We might put down another, much smaller cube for
the sofa and position it carefully in the room. Initially, this cube is simply a placeholder.
e same approach is taken to add a couple of stued chairs and a coee table. We would
likely add some smaller models later, like lamps and books, things to give the room a
eshed-out feeling. Incrementally these placeholders can be transformed into real furni-
ture, or the pieces of furniture might be built in another scene and imported. Either way,
we must begin with a good visual sense of the overall geometry of the room.
e coee table is likely to be composed of four individual legs and a top, all made from
polygon cubes. e legs will have to have materials assigned to them separately, each with
its own wood grain—just like in the real world. Aer all, the table is built out of pieces of
wood, not carved out of a solid block of wood.
e same do-it-naturally approach should be taken when adding light to the scene. e
scene is by its very nature articial, and so lights may illuminate specic aspects of it; the
initial lights could be a lamp on an end table and so light coming from the television.
Perhaps the sun or a streetlight might stream in through a window. ese things add more
models to the room.
Adding Detail with Precision
As you cra a given model, like a sofa or a lamp, be careful to add detailed geometry in the
form of vertices and edges, only where it is needed. is will make your job of adding materi-
als and animating models easier. It will also result in models that are easier to adapt and reuse.
Perhaps the tabletop has a wood perimeter with tiles and grout in the center. Initially,
you might only add the edges you need for the perimeter. Or you might build up the perim-
eter with the intention of dropping tiles into the center. Later, you will decide on the num-
ber and shape of those tiles.
Choosing the Model Hierarchy
When you decide to move your table to a dierent place in the room, you want the legs to go
with the top. e legs can be “parented” to the top. is is dierent than “combining” the several
objects that make up the table into a single object. By leaving the legs as independent objects, we
could more easily animate our table by letting the legs fold up, as a card table’s legs fold.
To make one (polygon) object the child of another, rst, go to:
any Main Menu → Window → Outliner
Select the (polygon) object and with your MMB (middle mouse button) drag and drop it
onto the (polygon) object you want to serve as the parent.
To combine multiple objects into a single object, select the rst object, then with your
Shi key down, select the next, and with your Shi key still down, continue selecting until
you have selected all of the objects. en choose:
Polygons Main Menu → Mesh → Combine
(From here on out we will refer to this process of selecting multiple objects at once as
a “Shi-select.”)
48 ◾ 3D Animation for the Raw Beginner Using Maya
Building Models in Separate Scenes
and Using Display Layers
You might also want to create each model in its own scene,
and then import them into the living room scene. It’s a good
idea to keep your work area uncluttered by not trying to
create too many objects/models in the same Maya scene.
Models can be rescaled aer they are imported into a scene.
It’s their relative proportions that are important initially.
You can also selectively make objects invisible in a scene
by arranging the objects in your scene into layers and only
showing specic layers.
Let’s suppose we have a scene with two horses in it, and
they are partly obscuring each other. We can create what are
called “display layers” in this scene by clicking on the icon
on the far upper right of the Main Window; see Figure3.1.
en we Shi-select the objects we want in the layer (in this
case, one of the horses), then select the Layers tab at the bot-
tom right of the Main Window, and then click on Create
Layer from Selected. See Figure3.2, where we have placed
the green horse in a layer by itself. You can now toggle on
and o the visibility of that layer by clicking on the V associ-
ated with that layer, as seen in Figure3.3. (e horse used in
Figure 3.2 is a base model provided with Autodesk Mudbox.)
In general, you can use display layers to selectively con-
ceal and reveal parts of a complex scene you are working on.
Create Versions of Models That You Can Retreat To
Finally, a beginner should always keep a series of versions
of each model. It’s good to number them: sofa1, sofa2, and
so on. en when you discover that your sofa has become
a lumpy bathtub, you can go back to an earlier version and
remodel from there.
In Sum
Modeling demands planning:
1. Choose a type of geometry (polygon, NURBS, or a mix)
with a modeling plan in mind.
2. Rough out your model rst.
3. Add detail (vertices/edges/polygons) only where it is
needed in order to esh out the 3D model.
FIGURE 3.1 e layers icon.
Modeling, Creating Materials, and Rendering ◾ 49
4. Create an object hierarchy with anima-
tion in mind. is will also make it eas-
ier to apply materials to selected objects
later.
5. Keep named, enumerated versions of
your scene le so you can retreat when
your modeling goes awry.
More on Layers in Maya
ere are actually three kinds of layering of
scenes that can be done with Maya. We have
looked at display layers. e other two can be
found in the Main Window, in the same place
as display layers. In Figure3.4, we see a set of
double doors. We will make a render layer out
of one of them.
Using render layers lets us put various
objects in a scene into different layers, and
FIGURE 3.2 Putting a horse in a layer.
FIGURE 3.3 Toggling a layer on and o.
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