Introducing Autodesk Maya 2012

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Dear Reader,

Thank you for choosing Introducing Autodesk Maya 2012. This book is part of a family of premium-quality Sybex books, all of which are written by outstanding authors who combine practical experience with a gift for teaching.

Sybex was founded in 1976. More than 30 years later, we’re still committed to producing consistently exceptional books. With each of our titles, we’re working hard to set a new standard for the industry. From the paper we print on, to the authors we work with, our goal is to bring you the best books available.

I hope you see all that reflected in these pages. I’d be very interested to hear your comments and get your feedback on how we’re doing. Feel free to let me know what you think about this or any other Sybex book by sending me an email at [email protected]. If you think you’ve found a technical error in this book, please visit http://sybex.custhelp.com. Customer feedback is critical to our efforts at Sybex.

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Vice President and Publisher

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To Max Henry

Acknowledgments

As this book goes into its eighth edition, I am thrilled that the Introducing Maya series is a favorite resource for students and teachers of Maya. Education is the foundation for a happy life, and with that in mind, I’d like to thank the outstanding teachers from whom I have had the privilege to learn. You can remember what you’ve been taught—or, just as important, you can remember those who have taught you. ■ I also want to thank my students, who have taught me as much as they have learned themselves. Juan Gutierrez, Victor J. Garza, Robert Jauregui, and Peter Gend deserve special thanks for helping me complete the models and images for this book. Thanks to the student artists who contributed to the color insert and, of course, thanks to my bosses, colleagues, and friends at work for showing me everything I’ve learned and making it interesting to be in the effects business. Special thanks to HP for their support and keeping me on the cutting edge of workstations. • Thanks to my editors at Sybex and the folks at Autodesk for their support and help and for making this process fun. Thanks to the book team for bringing it all together: Mariann Barsolo, Amy Breguet, and Elizabeth Campbell. My appreciation also goes to technical editor, Keith Reicher. ■ Finally, special mad props go to my friends Bill, Mark, Frank, Terry, and Brett. • Thank you to my mom and brothers for your strength, wisdom, and love throughout. And a special thank-you to my lovely wife Randi and our son Max Henry for putting up with the long nights at the keyboard; the grumpy, sleep-deprived mornings; and the blinking and buzzing of all my machines in our apartment. Family!

About the Author

Dariush Derakhshani is a supervisor for Zoic Studios, a creative studio with offices in Culver City, California, and Vancouver, British Columbia. Dariush has been working in CG for more than 15 years and teaching classes in CG and effects production for close to 14. He is the best-selling author of a handful of books, including the popular Introducing Maya series.

Dariush started using AutoCAD software in his architecture days and then migrated to using 3D programs when his firm’s principal architects needed to show their clients design work on the computer. Starting with Alias PowerAnimator version 6, which he encountered when he enrolled in the University of Southern California Film School’s Animation program, and working for a short while in 3ds Max before moving on to Maya jobs, Dariush has been using Autodesk animation software for the past 17 years.

He received an MFA in Film, Video, and Computer Animation in 1997 from USC. Dariush also holds a BA in Architecture and Theatre from Lehigh University in Pennsylvania and worked at a New Jersey architecture firm before moving to Los Angeles for film school. He has worked on feature films, music videos, and countless commercials as a 3D animator and VFX supervisor, garnering honors from the London International Advertising Awards, the ADDY Awards, the Telly Awards, and a nomination from the Visual Effects Society Awards. He is bald and has flat feet.

Introduction

Welcome to Introducing Autodesk Maya 2012 and the world of computer-generated imagery (CGI). Whether you’re new to 3D graphics or venturing into Autodesk’s powerhouse animation software from another 3D application, you’ll find this book a perfect primer. It introduces you to Maya and shows how you can work with Maya to create your art, whether it’s animated or static in design.

The first edition of this book was written out of the author’s desire for a solid, comprehensive, and yet open-ended teaching material about Maya for his classes. This book exposes you to all the facets of Maya by introducing and explaining its tools and functions to help you understand how Maya operates. In addition, you’ll find hands-on examples and tutorials that give you firsthand experience with the toolsets. Working through these will help you develop skills as well as knowledge. These tutorials expose you to various ways of accomplishing tasks with this intricate and comprehensive artistic tool.

Finally, this book explains workflow. You’ll learn not only how specific tasks are accomplished, but why—that is, how they fit into the larger process of producing 3D animation. By doing that, these chapters should give you the confidence to venture deeper into Maya’s feature set on your own or by using any of Maya’s other learning tools and books as a guide.

It can be frustrating to learn a powerful tool such as Maya, so it’s important to remember to pace yourself. The number-one complaint of readers of books like this is a sense that either the pace is too fast or the steps are too complicated or overwhelming. That’s a tough nut to crack, to be sure, and no two readers are the same. But this book offers you the chance to run things at your own pace. The exercises and steps may seem challenging at times, but keep in mind that the more you try—even the more you fail at some attempts—the more you’ll learn about how to operate Maya. Experience is the key to learning workflows in any software program, and with experience comes failure and aggravation. Nevertheless, try and try again, and you’ll see that further attempts will be easier and more fruitful.

Above all, this book aims to inspire you to use Maya as a creative tool to achieve and explore your own artistic vision.

What You’ll Learn from This Book

Introducing Autodesk Maya 2012 will show you how Maya works and introduce you to every part of the toolset to give you a glimpse of the possibilities available with Maya.

You’ll learn the basic concepts underlying animation and 3D and how to work with the Maya interface. You’ll then learn the basic methods of modeling—creating objects and characters that appear to exist in three-dimensional space and that can be animated. You’ll also explore shading and texturing—the techniques of applying surfaces to the objects you create—and you’ll learn how to create lights and shadows in a scene. Animation is an enormously rich topic, but the practice and theory provided here will give you a solid footing. Next, you’ll learn how to control the process of rendering, turning your images into files that can be viewed. Perhaps Maya’s most dazzling capability is its dynamics engine, software that allows you to make objects behave as if controlled by the real-world laws of physics.

After you’ve finished this book and its exercises, you’ll have experience in almost everything Maya offers, giving you a solid foundation on which to base the rest of your Maya and CGI experience.

The goal of this book is to get you familiar enough with all the parts of Maya that you can work on your own and start a long, healthy education in a powerful and flexible tool.

You will, however, learn the most from yourself.

Who Should Read This Book

Anyone who is curious about learning Maya or who is migrating from another 3D software package can learn something from this book. Even if you’re highly experienced in another 3D package such as NewTek’s LightWave or XSI, you’ll find this book helpful in showing you how Maya operates, so you can migrate your existing skill set quickly and efficiently. By being exposed to everything Maya has to offer, you’ll better understand how you can use its toolset to create or improve on your art and work.

If you already have cursory or even intermediate experience with Maya, culled from time spent learning at home, you can fill many holes with the information in this book as well as expand your experience. Self-education is a powerful tool, and the more you expose yourself to different sources, opinions, and methods, the better educated you’ll be.

In addition, this book is invaluable for teachers in the CG field. This book was written to cater to those who want to pick up the fundamentals of Maya as well as those who want to teach classes based around a solid body of course material. You won’t find a better basis for a class when you combine this book with your own curriculum.

How to Use This Book

Introducing Autodesk Maya 2012 approaches the subject in a linear fashion that tracks how most animation productions are undertaken. But the book has numerous cross-references, to make sure the chapters make sense in any order you may want to tackle them. You can open this book to any chapter and work through the tutorials and examples laid out for the Maya task being covered. Feel free to browse the chapters and jump into anything that strikes your fancy. However, if you’re completely new to CG, you may want to take the chapters in order.

Although you can learn a lot just by reading the explanations and studying the illustrations, it’s best to read this book while you’re using Maya 2012 so that you can try the exercises for yourself as you read them. If you don’t already have Maya, you can download an educational license or a 30-day trial version of the software at www.autodesk.com/maya. This book refers to a companion web page (www.sybex.com/go/intromaya2012) that contains all the example and support files you’ll need for the exercises in the text, which is valuable as an educational aid. You can use the example files to check the progress of your work, or you can use them as a starting point if you want to skip ahead within an exercise. The latter can save the more experienced reader tons of time. You’ll also find it valuable to examine these files in depth to see how scenes are set up and how some of the concepts introduced in the book are implemented. Because Maya is a complex, professional software application, the exercises are both realistically ambitious and simple enough for new users to complete. Take them one step at a time and find your own pace, accepting aggravations and failures as part of the process. Take your time; you’re not working on deadline—yet.

How This Book Is Organized

Chapter 1, Introduction to Computer Graphics and 3D, introduces you to common computer graphics terms and concepts to give you a basic overview of how CG happens and how Maya relates to the overall process. This chapter explores the basics of CG creation and its core concepts. In addition, it describes the process of CG production and discusses how to establish a commonly used workflow.

Chapter 2, Jumping in Headfirst, with Both Feet, creates a simple animation to introduce you to Maya’s interface and workflow and give you a taste of how things work right off the bat. By animating the planets in our solar system, you’ll learn basic concepts of creating and animating in Maya and how to use its powerful object structure.

Chapter 3, The Maya 2012 Interface, presents the entire Maya interface and shows you how it’s used in production. Beginning with a roadmap of the screen, this chapter also explains how Maya defines and organizes objects in a scene while you are set to the task of building a decorative box model.

Chapter 4, Beginning Polygonal Modeling, is an introduction to modeling concepts and workflows in general. It shows you how to start modeling using polygonal geometry to create various objects, from a human hand to a complex locomotive engine.

Chapter 5, Modeling with NURBS, Subdivisions, and Deformers, takes your lesson in modeling a step further. It shows you how to model with deformers and surfacing techniques, using NURBS to create a patch model detail for the locomotive you modeled in Chapter 4. You’ll also use subdivision surfaces, a hybrid between polygons and NURBS, to create a starfish.

Chapter 6, Practical Experience, rounds out your modeling lessons with two comprehensive exercises showing you how to model a child’s toy wagon using polygons as well as NURBS surfacing.

Chapter 7, Maya Shading and Texturing, shows you how to assign textures and shaders to your models. Using the toy wagon you created in Chapter 6, you’ll learn how to texture it to look like a real toy wagon as well as lay out its UVs for proper texture placement. Then, you’ll create detailed photorealistic textures based on photos for the decorative box model. You’ll also learn how to take advantage of Maya 2012’s ability to work with layered Photoshop files.

Chapter 8, Introduction to Animation, covers the basics of how to animate a bouncing ball using keyframes and moves on to creating more complex animation—throwing an axe and firing a catapult. You’ll also learn how to import objects into an existing animation and transfer animation from one object to another, a common exercise in professional productions. In addition, you’ll learn how to use the Graph Editor to edit and finesse your animation as well as animate objects along paths.

Chapter 9, More Animation! expands on Chapter 8 to show you how to use Maya’s skeleton and kinematics system to create a simple walk cycle. This chapter also covers how to animate objects by using relationships between them. A thrilling exercise shows you how to rig your locomotive model from Chapter 4 for automated animation, one of Maya’s most productive uses.

Chapter 10, Maya Lighting, begins by showing you how to light a 3D scene as you learn how to light the wagon you modeled and textured earlier in the book. It also shows you how to use the tools to create and edit Maya lights for illumination, shadows, and special lighting effects. mental ray for Maya’s Physical Sun and Sky feature is explored in this chapter as an introduction to some sophisticated techniques for mental ray lighting.

Chapter 11, Maya Rendering, explains how to create image files from your Maya scene and how to achieve the best look for your animation using proper cameras and rendering settings. You’ll work with displacement maps to create details in a model. You’ll also learn about the Maya renderer, the Vector renderer, and Final Gather using HDRI and image-based lighting through mental ray for Maya, as well as raytracing, motion blur, and depth of field. You’ll have a chance to render the decorative box to round out your skills.

Chapter 12, Maya Dynamics and Effects, introduces you to Maya’s powerful dynamics animation system as well as nParticle technology. You’ll animate pool balls colliding with one another using rigid body dynamics, and using nParticle animation, you’ll create steam to add to your locomotive scene from Chapter 4. This chapter also shows you how to use Paint Effects to create animated flowers and grass within minutes, and it introduces you to using toon shading to achieve a cartoon look to your renders.

Hardware and Software Considerations

Because computer hardware is a quickly moving target, and Maya now runs on three distinct operating systems (Windows 2000/XP/Vista/Windows 7, Linux, and Mac OS X), specifying which hardware components will work with Maya is something of a challenge. Fortunately, Autodesk has a qualified hardware page on its website that describes the latest hardware to be qualified to work with Maya for each operating system. Go to the following site for the most up-to-date information on system requirements:

www.autodesk.com/maya

Although you can find specific hardware recommendations on these web pages, some general statements can be made about what constitutes a good platform on which to run Maya. First, be sure to get a fast processor; Maya eats through CPU cycles like crazy, so a fast processor is important. Second, you need lots of RAM (memory) to run Maya: at least 2 GB, but 8 GB is good to have, especially if you’re working with large scene files or are on a 64-bit system. Third, if you expect to interact well with your Maya scenes, a powerful video card is a must—although Maya will mosey along with a poor graphics card, screen redraws will be slow with complex scenes, which can quickly become frustrating. You may want to consider a workstation graphics card for the best compatibility (rather than a consumer-grade gaming video card). Several companies make entry-level through top-performing workstation cards to fit any budget. A large hard disk is also important—most computers these days come with huge drives anyway.

Fortunately, computer hardware is so fast that even laptop computers can now run Maya well. Additionally, even hardware that is not officially supported by Autodesk can often run Maya—just remember that you won’t be able to get technical support if your system doesn’t meet the company’s qualifications.

The Next Step

By the time you finish Introducing Autodesk Maya 2012, you’ll have some solid skills for using Maya. When you’re ready to move on to another level, be sure to check out other Maya titles from Sybex at www.sybex.com.

You can contact the author at www.koosh3d.com. You may also go to the book’s web page at www.sybex.com/go/intromaya2012.

Chapter 1

Introduction to Computer Graphics and 3D

This book will introduce you to the workings of 3D animation (called computer graphics, or CG) with one of the most popular programs on the market, Autodesk Maya. It will introduce you to many of Maya’s features and capabilities with the intent of energizing you to study further.

Having said that, let’s face a basic fact: The best way to succeed at almost anything is to practice. Prepare to go through the exercises in this book, but also try to think of exercises and projects that can take you further in your learning process. A book, class, or video can take you only so far; the rest is up to you. Imagination and exploration will serve you well.

This is not to say you can’t be a casual visitor to working in CG—far from it. Playing around and seeing what you can create in this medium is just flat-out fun. Don’t lose sight of that. If you feel the enjoyment slipping away, step away from the screen for a while. Understanding your own learning pace is important.

Throughout this book, you’ll learn how to work with Maya tools and techniques at a pace you set for yourself. This chapter will prepare you for the hands-on study that follows by introducing the most important CG concepts and the roles they will play in your Maya work. When you’re learning how to work with Maya, the most important concept is discovering how you work as an artist. If you have a basic understanding of the methodology and terms of computer art and CG, you can skim or even skip this chapter and jump right into working with Maya.

Topics in this chapter include:

Art?

Computer graphics

The stages of production

The CG production workflow

Core concepts

Basic film concepts

Art?

Art, in many instances, requires transcendence of its medium; it speaks of its own accord. Art goes beyond the mechanics of how you create it (whether by brush or mouse) and takes on its own life. Learning to look beyond what you’re working with and seeing what you’re working for is the key to creating art with CG. Try not to view this experience as learning a software package, but as learning a way of working to an end. As you begin learning CG with Maya, you acquire a new language—a new form of communication. Keep in mind that the techniques you acquire are only a means to the end.

Relax and enjoy yourself.

It’s hard to relax when you’re trying to cram so much information into your brain. But keep in mind that you should try not to make this experience about how a software program works; instead, make it about how you work with the software. Maya is only your tool.

When hiring professional 3D artists, CG studios keenly look for a strong artistic sense, whether in a traditional portfolio or a CG reel. Therefore, it’s paramount to fortify the artist within yourself and practice traditional art such as life drawing, photography, painting, or sculpture as you learn CG, beginning with the core principles introduced in this first chapter. Keep in mind that the computer you’ll be using for 3D work is nothing more than a tool. You run it; it doesn’t run you.

3D is a part of the daily visual lexicon. With the availability of inexpensive and fast computers, everyone can create their own CG projects. Artists everywhere are adding the language of CG to their skill set. So before you start learning a particular CG tool—Maya, in this case—make sure you have a grasp of the fundamental issues underlying CG. It’s important that you do.

Computer Graphics

CG and CGI are the abbreviations for computer graphics and computer graphics imagery, respectively, and are often used interchangeably. CG literally refers to any picture or series of pictures that is generated by an artist on a computer. However, the industry convention is to use the terms CG and CGI to refer to 3D graphics and not to images created using 2D image or paint programs such as Adobe Photoshop.

Most 2D graphics software is bitmap based, whereas all 3D software is vector based. Bitmap-based software creates an image as a mosaic of pixels, filled in one at a time. Vector-based software creates an image as a series of mathematical instructions from one calculated, or graphed, point to another. This much more powerful method for creating graphics is behind all the impressive CG images you’ve seen in movies, videogames, and so on. It’s also the method for the images you’ll soon create with Maya. You’ll learn more about vectors and bitmaps in the section Computer Graphics Concepts later in this chapter.

If you’re familiar with 2D graphics software, such as Adobe Illustrator or Adobe Flash, you already know something about vectors. Maya and other 3D graphics tools add the calculation of depth. Instead of drawing objects on a flat plane, they’re defined in three-dimensional space. This makes the artist’s job fairly cerebral and very different than it is for 2D art; in 3D art, there is more of a dialogue between the left and right sides of the brain. When working with 3D graphics tools, you get a better sense of manipulating and working with objects, as opposed to dealing with the lines, shapes, and colors used to create 2D images.

A Preview of the CG Process

The process of creating in CG requires that you either model or arrange prebuilt objects in a scene, give them color and light, and render them through a virtual camera to make an image. In essence, you create a scene that tells the computer what objects are in the scene, where the objects are located, what the colors and textures of the objects are, what lighting is available, and which camera to use in the scene. It’s a lot like directing a live-action production, but without any actor tantrums.

A large community on the Web provides free and for-pay models that you can use in your scenes. Sites such as www.turbosquid.com and www.archive3d.net can cut out a lot of the time you might spend creating all the models for a CG scene. Taking advantage of this gives you the chance to skip at least some of the modeling process, if that isn’t your thing.

With CG, you work in 3D space—an open area in which you define your objects, set their colors and textures, and position lights as if you were setting up for a live photo shoot. CG is remarkably analogous to the art and practice of photography and filmmaking.

Photographers lay out a scene by placing the subjects into the frame of the photo. They light the area for a specific mood, account for the film qualities in use, adjust the lens aperture, and fine-tune for the colors of the scene. They choose the camera, film, and lens based on their desired result. Then, they snap the pictures and digitally transfer them or develop them to paper. Through this process, a photo is born.

After you build your scene in 3D using models, lights, and a camera, the computer renders the scene, converting it to a 2D image. Through setup and rendering, CGI is born—and, with a little luck, a CG artist is also born.

Rendering is the process of calculating lights and shadows, the placement of textures and colors on models, the movement of animated objects, and so on to produce a sequence of 2D pictures that effectively shoot your virtual scene. Instead of an envelope of 4×6 glossy prints, you get a sequence of 2D computer images (or a QuickTime or AVI [Audio Video Interleave] movie file) that sit on your hard drive waiting to be seen, and invariably commented on, by your know-it-all friends.

In a nutshell, that is the CG process. You’ll need to practice planning and patience, because CG follows conventions that are different from those for painting programs and image editors. The CG workflow is based on building, arrangements, and relationships. But it’s an easy workflow to pick up and master in time. It can be learned by anyone with the desire and the patience to give it a try.

Animation

Animation is change over time. In other words, animation is the simulation of an object changing over a period of time, whether it’s that object’s position or size, or even color or shape. In addition to working in the three dimensions of space, Maya animators work with a fourth dimension: time.

All animation, from paper flipbooks to film to Maya, is based on the principle that when we see a series of rapidly changing images, we perceive the changing of the image to be in continuous motion. If you have a chance to pause and step through an animated film, frame by frame, on your DVD player or DVR, you’ll see how animation comes together, literally step by step.

To create CG animation yourself, you have to create scene files with objects that exhibit some sort of change, whether through movement, color shift, growth, or other behavior. But just as with flipbooks and film animation, the change you’re animating occurs between static images, called frames, a term carried over from film. You define the object’s animation using a timeline measured in these single frames.

You’ll learn more in the section Basic Animation Concepts later in this chapter. For now, let’s move on to the stages of CG production.

The Stages of Production

The CG animation industry inherited a workflow from the film industry that consists of three broad stages: preproduction, production, and postproduction. In film, preproduction is the process in which the script and storyboards are written, costumes and sets are designed and built, actors are cast and rehearse, the crew is hired, and the equipment is rented and set up. In the production phase, scenes are taped or filmed in the most efficient order. Postproduction (often simply called post) describes everything that happens afterward: The scenes are edited into a story; a musical score, sound effects, and additional dialogue are added; and visual effects may also be added. (In a film that has special effects or animation, the actual CG creation is usually completed in postproduction. However, it may start in the preproduction phases of the film or project.)

Although the work performed at each stage is radically different, this framework is useful for understanding the process of creating CG as well.

Preproduction

Preproduction for a CG animation means gathering reference materials, motion tests, layout drawings, model sketches, and such together to make the actual CG production as straightforward as possible. Whether you’re working on a small job or a complex film, entering into production without a good plan of attack will not only cause trouble, but also stunt the growth of your project.

In the real world, preproduction is part of every CG animation project. For the tutorial projects in this book, the sketches and other files supplied on the book’s web page are your preproduction; however, try to gather as much information as you can about the objects you’ll create beyond what is presented. Having different perspectives on a subject is the key to understanding it.

The Script

To tell a story, CG or not, you should put it in words. A story doesn’t need to contain dialogue for it to benefit from a script. Even abstract animations benefit from a detailed explanation of timings and colors laid out in a treatment (because there is likely no dialogue). The script or treatment serves as the initial blueprint for the animation, a place where you lay out the all-important intent.

The Storyboard

A storyboard is a further definition of the script. Even a rudimentary storyboard with stick figures on notebook paper is useful to a production. You break the script into scenes, and then you break those scenes into shots. Next, you sketch out each shot in a panel of a storyboard. The panels are laid out in order according to the script to give a visual and linear explanation of the story. Storyboards are useful for planning camera angles (framing a shot), position of characters, lighting, mood, and so on. Figure 1-1 shows a rough storyboard for a character falling asleep while watching TV.

Figure 1-1: A storyboard helps define the action.

The Conceptual Art

Conceptuals are the design elements that you may need for the CG production. Typically, characters are drawn into character sheets in three different neutral poses: from the front, from the side, and from an angle called a ¾ view. You can also create color art for the various sets, props, and characters to better visualize the colors, textures, and lighting that will be needed. Props and sets are identified from the script and boards and then sketched out into model sheets. The better you visualize the conceptual art, the easier it will be to model, texture, and light everything in CG.

Production

Production begins when you start creating models from the boards, model sheets, and concept art. You model the characters, sets, and props, and then you assign textures (colors and patterns). The animators take the models and animate everything according to the boards and script. The sequences are rendered in low quality for dailies and checked for accuracy and content.

The CG production phase can involve a variety of steps. The specific steps are defined by the needs of the production. Most of the CG techniques you’ll learn in this book are part of the production phase. To make a long story short, 3D scenes are created, lit, and animated in the production phase.

Postproduction

After all the scenes have been set up with props and characters and everything is animated, postproduction can begin. Postproduction for a CG project is similar to postproduction for a film. This is where all of a CG film’s elements are brought together and assembled into final form.

Rendering

Rendering is the process by which the computer calculates how everything in the scene should look and then displays it. As you’ll learn throughout this book, the decisions you make in creating the objects in a scene can make a big difference in how the rest of the process goes.

Rendering makes significant processing demands on your computer, usually requiring the full attention of your PC. This can take a considerable amount of time. You can render one scene while another scene is in production, but asking a computer that is rendering to multitask isn’t advisable in most cases.

When everything is rendered properly, the final images are sorted and the assembly of the CG project begins. Rendering is discussed more fully in Chapter 11, Maya Rendering.

We’ll take a quick look at three more postproduction activities: compositing, editing, and adding sound. These are advanced topics, and complete coverage is beyond the scope of Introducing Autodesk Maya 2012. However, a multitude of books are available on these topics for further study, and some are listed at the end of this chapter.

Compositing

Quite often, CG is rendered in different layers and segments, which need to be put back together. In a particular scene, for example, multiple characters interact. Each character is rendered separately from the others and from the backgrounds. They’re then put together in compositing, or the process of bringing together scene elements that were created separately to form the final scene. Maya makes this process easier with render layers, which you’ll experience in Chapter 11.

Compositing programs such as Maya Composite, Nuke, Digital Fusion, and After Effects allow you to compose CG elements together and give you some additional control over color, timing, and a host of other additions and alterations you can make to the images. Compositing can greatly affect the look of a CG project and can be an integral part of CG creation.

Many new animators try to generate their final images in a single rendering of their scene, but you don’t need to do that. Realizing the component nature of CG is important; you can use components to your advantage by rendering items separately and compositing them together in the finishing stage. This approach gives you a lot of control in finishing the images to your satisfaction without always having to go back, change the scene, and re-render it.

Editing

The rendered and composited CG footage is collected and edited together to conform to the script and boards. Some scenes are cut or are moved around to heighten the story. This process is essentially the same as for film editing, with one big difference: the amount of footage used.

A typical film uses a fraction of all the film or video that is shot. But because creating CG is typically more time-consuming and expensive than shooting live action, scenes and shots are often tightly arranged in preproduction boards so not much effort is wasted. The entire production is edited with great care beforehand, and the scenes are built and animated to match the story, almost down to the frame. Consequently, the physical editing process consists mostly of assembling the scenes into the sequence of the story. This is also why a good preproduction process is important. When you plan out what you want to get, you’re much more likely to get it.

Sound

Sound design is critical to CG because viewers associate visuals with audio. A basic soundtrack can give a significant punch to a simple animation by helping to provide realism, mood, narrative, and so on, adding a greater impact to the CG.

Sound effects, such as footsteps, are inserted to match the action on the screen. This type of sound is also known in film as Foley sound. Music is scored and added to match the film. Quite often, the dialogue or musical score inspires a character’s actions or body language. Again, this is much the same procedure as in film, with one exception. In the event that a CG project requires dialogue, the dialogue must be recorded and edited before CG production can begin. Dialogue is a part of the preproduction phase as well as a component of postproduction. This is because animators need to hear the dialogue being spoken so they can coordinate the lip movements of the characters speaking, a process known as lip-synch.

How It All Works Together

The process behind making a South Park episode is a perfect workflow example. Although the show appears to be animated using paper cutouts, as was the original Christmas short, the actual production work is now done using Maya. In preproduction on a typical episode, the writers hammer out the script, and the voice talent records all the voices before the art department creates the visuals for the show. The script is storyboarded, and copies are distributed to all the animators and layout artists.

At the beginning of the production phase, each scene is set up with the proper backgrounds and characters in Maya and then handed off for lip-synch, which is the first step in the animation of the scene. The voices are digitized into computer files for lip-synch animators who animate the mouths of the characters. The lip-synched animation is then passed to character animators who use the storyboards and the soundtrack to animate the characters in the Maya scene.

The animation is then rendered to start the post, edited together following the boards, and then sent back to the sound department for any sound effects needed to round out the scene. The episode is assembled and then sent off on tape for broadcast.

The CG Production Workflow

Modeling almost always begins the CG process, which then can lead into texturing, and then to animation (or animation and then texturing). Lighting should follow, with rendering pulling up the rear as it must. (Of course, the process isn’t completely linear; you’ll often go back and forth adjusting models, lights, and textures throughout the process.) Chapters 4 through 11 follow this overall sequence, presenting the major Maya operations in the same order you’ll use in real-world CG projects.

Modeling

Modeling, the topic of Chapters 4 through 6, is usually the first step in creating CG. It’s the topic that garners a lot of coverage in publications and captures the interest of most budding CG artists. Downloading or purchasing models from the Internet can often cut down the amount of time you spend on your project. This, of course, assumes you’re not a fan of modeling and prefer to spend your time animating or working on texturing and lighting.

There are many modeling techniques, and each could be the subject of its own series of books. The choice of which technique to use usually depends on the modeler’s taste and preferred workflow. The choices are among polygonal modeling (Chapter 4, Beginning Polygonal Modeling), NURBS modeling, and subdivision surface (SubD) modeling (Chapter 5, Modeling with NURBS, Subdivisions, and Deformers). Knowing how an object is used in a scene gives you its criteria for modeling. You never want to spend more time on a model than is needed. Creating a highly detailed model for a faraway shot will waste your time and expand rendering times needlessly. You can create any required details that are seen from afar by just adding textures to the model. However, if that model is featured prominently in a close-up, it needs as much detail as possible because viewers will see more of it. You’ll learn more about this aspect of modeling in Chapter 4.

When you’re starting out, it’s a good idea to lavish as much attention on detail as you can; this can teach you perhaps 70 percent of what you can learn about modeling, which in turn will benefit your overall speed and technique. As you gain more experience, you’ll be able to discern exactly how much detail to add to a scene and not go overboard.

Because your computer stores everything in the scene as vector math, the term geometry refers to all the surfaces and models in a scene.

Texturing

When the models are complete, it’s a good idea to begin texturing and shading, the process of applying colors and textures to an object to make it renderable. When you create an object in Maya, for example, a simple gray default shader is automatically assigned to it that will let you see the object when you light and render the scene. In Figure 1-2, an elephant model is shown, with textures applied to its lower body.

Because the textures may look different after animating and lighting the scene, it’s wise to leave the final adjustments for later. Just as a painter will pencil in a sketch before adding details, you don’t need to make all the shading adjustments right away; you can return to any part of your scene in Maya and adjust it to fine-tune the picture.

You’ll learn more about texturing and shading in Chapter 7, Maya Shading and Texturing.

Figure 1-2: Texturing adds detail to an otherwise flat model.

Animation

You can make or break your scene with animation. We all have an innate sense of how things are supposed to move on a visceral level, if not an academic one. We understand how physics applies to objects and how people and animals move around. Because of this, viewers tend to be critical of CG’s motion if it’s not lifelike. Put bluntly, you know when something doesn’t look right, and so will the people watching your animation.

To animate something properly, you may need to do quite a lot of setup beyond just modeling. Depending on the kind of animating you’ll be doing, you may need to set up the models for however you’ve decided to animate them. For example, for character animation you’ll need to create and attach an armature, or skeleton, to manipulate the character and to make it move like a puppet in order to do your bidding.

Taking the models you’ve spent hours detailing and reworking and giving them life is thrilling and can make any detailed modeling and setup routine well worth the effort.

Chapter 8, Introduction to Animation, and Chapter 9, More Animation! cover animation techniques in Maya.

Lighting

CG is fundamentally all about light. Manipulating how light is created and reflected is what you’re doing with CG. Without light, we wouldn’t see anything, so it makes sense that simulating light is the most influential step in CG. Lighting can drastically alter the look of your scene; it greatly affects the believability of your models and textures and creates and heightens mood.

During the lighting step, you set up virtual lights in your scene to illuminate your objects and action. Although you can set up some initial lights during the texturing of the scene, the serious lighting should be the last thing you do, aside from changes and tweaks.

The type and number of lights you use in a scene greatly affect not just the look of your scene, but also the amount of time the scene takes to render. Lighting becomes a careful dance between pragmatics and results. It’s perhaps the subtlest part of CG to master.

When you gain more experience with lighting, you’ll notice that it affects every part of your CG creation. Before long, you’ll start modeling differently—that is, modeling with the final lighting of the scene in mind. Texturing will change when you keep lighting techniques in mind. Even your animation and staging will change a bit to take better advantage of efficient, powerful lighting.

As you’ll learn in Chapter 10, Maya Lighting, virtual lights in Maya are similar to lights used in the real world, from a single point of light, such as a bulb, to directed beams, such as spotlights.

Rendering

At this stage, your computer takes your scene and makes all the computations it needs to create raster (bitmapped) images for your movie. Rendering time depends on how much geometry is used in the scene as well as on the number of lights, the size of your textures, and the quality and size of your output: the more efficient your scene, the shorter the rendering times.

A lot of people ask how long they should expect their renders to take or how long is too long for a frame to render. It’s a subjective question with no real answer. Your frames will take as long as they have to for them to look the way you want. Of course, if you have tight time or budgetary constraints, you need simple scenes to keep the render resources and times to a minimum. In production, you’re always short on time, so having the most efficient pipeline possible will be your savior. If you don’t work efficiently, your producer or supervisor eventually will tire of hearing, But I’m still rendering.

That being said, it’s important to understand how a scene is put together before you learn to put a scene together efficiently. While you’re learning, use as many lights and as much geometry as you think you need for your scenes. The more experience you gain, the more efficient your eye will become.

Core Concepts

CG animation draws from many disciplines. While learning Maya, you’ll work with concepts derived not only from computer graphics, but also from design, film and cinematography, and traditional animation. Here’s a summary of the most important of those concepts as they apply to Maya.

Computer Graphics Concepts

Knowing a bit about the general terminology and methodology of computer graphics will help you understand how Maya works. Let’s begin with the crucial distinction between raster (bitmapped) and vector graphics and how this distinction affects you as a Maya user.

Raster Images

Raster images (a.k.a. bitmapped images) make up the world of computer images today. A raster or bitmap image is a mosaic of pixels; an arrangement of colored pixels onscreen or dots on a print to display an image. Everything you create in Maya will eventually be seen as a raster image, even though you first create it using vectors.

Raster image programs, such as Photoshop, let you adjust existing settings such as color, size, and position for all or part of an image. They let you paint onto a scanned picture or a virtual canvas to adjust or create the pixels yourself. These programs affect pixels directly, giving you the tools to change pixels to form images. For instance, you can use a scanned photo of your house in Photoshop to paint the side of the house red to see what it might look like before you run down to the local paint store.

The resolution of an image is defined by the number of pixels in the horizontal and vertical directions. Because they’re based on a grid of a fixed size, raster images don’t scale up well beyond a certain point. The closer you get to a raster image, the bigger the pixels become, making the image look blocky, or pixelated. To make large raster images, you need to begin with a higher resolution. The higher the resolution, the larger the file size will be. Figure 1-3 shows what happens when you blow up a raster image.

Figure 1-3: A raster image at its original size (left) and blown up several times (right)

Most common raster displays are television or computer screens. In fact, the term raster originally referred to the display area of a television or computer monitor. Every image generated by a computer, therefore, must either begin as a raster image or be rasterized as part of rendering for display.

Vector Images

Vector images are created in a completely different way. They’re formed using mathematical algorithms and geometric functions. Instead of defining the color of each and every pixel in a grid of a raster image, a vector image uses coordinates and geometric formulas to plot points that define areas, volumes, and shapes.

Popular vector-based image applications include Adobe Illustrator and Flash, as well as practically all computer-aided design (CAD) programs, such as AutoCAD and SolidWorks. These programs let you define shapes and volumes and add color and texture to them through their toolsets. They store the results in scene files containing coordinates and equations of points in space and the color values that have been assigned to them. This vector information is then converted into raster images (called rasterization) through rendering so you can view the final image or animation.

When scaled, vector graphics don’t suffer from the same limitations as raster images. As you can see in Figure 1-4, vectors can be scaled with no loss of quality; they will never pixelate.

Figure 1-4: A vector image at its original size (left) and blown up quite a bit (right)

Motion in vector programs is stored not by a long sequence of image files, but through changes in positions of the geometry and in the math that defines the shapes and volumes. When a Flash cartoon is played on a website, for example, the information downloaded and fed to your computer is in vector form. Your computer then renders this information on the fly in real time into a raster display of the content that you can (you hope) enjoy on your screen.

When you work in Maya, vectors are displayed as wireframes. When you finish your scene, Maya renders the image, converting the vector information into a sequence of raster images you can play back.

Image Output

When you’re done with your animation, you’ll probably want as many people as possible to see it (and like it!). To make that happen, you have to render it into a file sequence or a movie file. The file can be saved in any number of ways, depending on how you intend it to be viewed.

Color Depth

An image file stores the color of each pixel as three values representing red, green, and blue. Image type depends on how much storage is allotted to each pixel (the color depth). These are the color depths common to image files in CG production:

Grayscale The image is black and white with varying degrees of gray in between, typically 256 shades of gray. Grayscale images are good for rendering out black-and-white subjects as well as being used for some types of texture maps like displacement maps.

8-Bit Image File (a.k.a. 24-Bit Color Display) Referred to as 24-bit color display or True Color in desktop settings for Windows, each color channel is given 8 bits for a range of 256 shades of each red, green, and blue channel, for a total of 16 million colors in the image. This color depth gives good color quality for an image and is widely used in most animation applications. Most of your renders from Maya will probably be as 8-bit image files, because most monitors are only capable of 8-bit color reproduction in playback.

16-Bit Image File Used in television and film work using such file types as TIFF16, a 16-bit image file holds 16 bits of information for each color channel, resulting in an impressive number of color levels and ranges. Each file can exceed several megabytes even at low resolutions. These files are primarily used in professional productions, although they’re being supplanted by the use of 32-bit images.

32-Bit Image File This is where the big kids play. Used primarily for film work but increasingly in general use, 32-bit image files, such as the OpenEXR format, give you an incredible amount of range in each color channel. This lets you adjust a wide range of tones and hues in your rendered output for the fullest detail. They’re pretty much standard for film work because outputting CG to film can require high levels of color and brightness range in the image.

High Dynamic Range Imagery (HDRI) HDRI images are 32-bit float images that are created by combining several digital photos into one image file. For example, photos are taken of a subject with different levels of light using various exposures during photography. With a 32-bit float file format, a lot of information can be stored about the colors in the image—that is, a very high bit depth is achieved. This way, you have a series of images that range from dark (with very fast exposure) to normal (with proper exposure time) to blown-out brightness (with overexposure). These different exposures are then compiled into a single HDR file format (.hdr) that represents a wider range of light and dark than a typical photo. These files are traditionally used as lighting setups, especially for scenes in which CG is integrated with a live-action background using image-based lighting (IBL), a concept we’ll touch on in Chapter 11.

Color Channels

As mentioned, each image file holds the color information in channels. All color images have red, green, and blue color channels that, when viewed together, give a color image. Each channel is a measurement of how much red, green, or blue is in areas of the image. A fourth channel, called the alpha channel, is used as a transparency channel. This channel, also known as the matte channel, defines which portions of the image are transparent or opaque. Not all image files have alpha channels. You can read more about alpha channels in Chapter 7.

File Formats

In addition to image types, several image file formats are available today. The most common is probably JPEG (Joint Photographic Experts Group), which is widely used on the Internet.

The main difference between file formats is how the image is stored. Some formats compress the file to reduce its size. However, as the degree of compression increases, the color quality of the image decreases.

The popular formats to render into from Maya