Modeling Basics

What Is Modeling?

Let's begin with a working definition of what modeling is in computer animation: 3D modeling is the process of creating three-dimensional surfaces using a computer, for the purpose of rendering them into a picture or a sequence of pictures. In fields such as the automobile industry or engineering, digital models are actually built with specific products in mind—their purpose is to create a physical model or prototype that will ultimately become a working automobile or a building. Rendering is only a stage they go through in order to get to their ultimate destination. For 3D artists working in computer animation, however, the ultimate destination is pictures that exist in TV, videos, or celluloid—all 2D environments.

Creating an Illusion

Digital space is a world of facades. If only the back and right walls of a room will be seen, it makes no sense to build the front or the left side. For the computer animator, modeling is all about creating illusions for the eye to feast on—build only what the eye (the camera) will see. This is why careful preproduction planning is so crucial and why well-organized production teams create detailed storyboards before they commit to building anything.

Good Models and Bad Models

Good models look good when rendered, and bad models look bad. It's that simple. The catch, of course, is that producing models that look good takes a lot of time and care, and producing great-looking models always takes a lot of sweat and effort. Tight schedules and deadlines often make this a difficult—if not an impossible—task.

Other less-obvious factors in the production environment also determine whether a model is good or bad, and these are just as important as the model's appearance. The two criteria for good modeling most frequently used in animation are how computationally heavy or light a model is and how well it can be set up for animation.

Improperly built models often end up being heavy, meaning they are built with too much geometry and can cause numerous problems for the animators or a loss of precious production time in rendering. A heavy model makes the computer's CPU work harder than it would otherwise need to. A light model, in contrast, does not have a lot of geometry for the computer to calculate and thus allows the animator to act more interactively with it, producing better animation in shorter time. It generally renders faster too.

Modeling Tools

Let's now look at some of Maya's modeling features. Maya has a vast array of tools that can aid in modeling. Here are some of the more basic and useful functions we will cover in this chapter:

• Templates

• Layers

• Isolated selection

• Pick-masking

• Snapping

• Freezing transformations

• Construction history

Templates

In Maya, templates are mainly used as guides for modeling. Objects that become templates remain visible but cannot be selected like other objects. The standard way to turn an object into a template is to select the object and then choose Display ® Object Display ® Template. You can also open the Attribute Editor (press Ctrl+A), choose Display, and toggle on Template.

Because you cannot select the templated object in the usual way by dragging, in order to untemplate it, you must either select it in the Outliner or the Hypergraph Editor, or use a selection mask and then toggle it back by choosing Display ® Object Display ® Untemplate.

You can also template objects by using the Layer Editor. A layer also has templating capability, and it is generally the more efficient way to template objects because it can handle groups. You access layers through the buttons above the Channel Box. You have three options for viewing them—layer only, Channel Box only, or both together.

The Layer Editor

"Techniques for Speeding Up Workflow," introduced the Layer Editor, an extremely useful tool for modeling. Originally created for Alias Power Animator, it came back in its original form in Maya 2 and has become even better with each new version of Maya. A layer creates an exclusive collection of objects that can be selected, hidden, or templated together. Essentially, a layer acts as a directory or a folder for objects to aid in organization and work efficiency.

Be sure you are familiar with the basic techniques presented for working with the Layer Editor:

• To display the Layer Editor if it has been turned off, choose Display ® UI Elements ® Channel Box/Layer Editor. If the Channel Box is showing but not the Layer Editor, click the second or the third button in the top-left corner of the Channel Box to display it.

• To create a new layer, choose Layers ® Create Layer from the Layer Editor's menu, or click the New Layer button—it's to the right and just below the menu.