Rigging for Games: A Primer for Technical Artists Using Maya and Python

435 Pages·2017·18.56 MB·English

by  Eyal Assaf

Rigging for Games
Rigging for Games: A Primer for Technical Artists Using Maya and Python is not just another step-
by-step manual of loosely related tutorials. Using characters from the video game Tin, it takes you
through the real-world creative and technical process of rigging characters for video games and
cinematics, allowing readers a complete inside look at a single project.
You’ll explore new ways to write scripts and create modular rigs using Maya and Python and
automate and speed up the rigging process in your creative pipeline. Finally, you’ll learn the most
efficient ways of exporting your rigs into the popular game engine Unity. This is the practical, start-
to-finish rigging primer you’ve been waiting for!
Enhance your skill set by learning how to efficiently rig characters using techniques
applicable to both games and cinematics
Keep up with all the action with behind-the-scenes images and code scripts
Refine your rigging skills with tutorials and project files available on the companion website
Eyal Assaf is a Technical Artist currently living and working in Toronto, Canada. A graduate from
the Ontario College of Art and Design, Eyal has been involved in the animation, gaming and
broadcast industries since the mid-90s when digital dinosaurs began to roam the big screens. His
wide range of experience led him to positions such as Visual Effects Supervisor on an award-winning
animated 3D television show as well as other lead positions in a variety of commercials, broadcast,
film, and game projects. He is also an internationally published illustrator in various trade
publications and teaches 3D and Design at college level.
Rigging for Games
A Primer for Technical Artists Using Maya and
Python
Eyal Assaf
CRC Press
Taylor & Francis Group
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Boca Raton, FL 33487–2742
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Library of Congress Cataloging-in-Publication Data
Assaf, Eyal.
 Rigging for games : a primer for technical artists using Maya and Python / Eyal Assaf.
  pages cm
 Includes bibliographical references and index.
1. Rigging (Computer animation) 2. Video games—Design. 3. Computer games—Design. 4. 
Python (Computer program language) 5. Maya (Computer file) I. Title.
 TR897.77.A87 2016
 006.6'96—dc23
 2015015031
ISBN: 978-0-415-74304-4 (hbk)
ISBN: 978-0-415-74305-1 (pbk)
ISBN: 978-1-315-81391-2 (ebk)
Typeset in Myriad Pro
by Apex CoVantage, LLC
Visit the Taylor & Francis Web site at http://www.taylorandfrancis.com and the CRC Press Web site
at http://www.crcpress.com
Contents
Acknowledgments
Introduction
Chapter 1: The Creative Cycle
From Page to Screen
Where Do Ideas Come From?
The Production Cycle
Pre-Production
Step 1: Planning the Story / Game Outline
Step 2: The Script / Game Design Document
Step 3: Concept Art
Step 4: Storyboards
Planning the Storyboard Scenes
Color Scripts
Step 5: Asset Lists
Step 6: Asset Management and Organization
Step 7: Animatic / First Playable Prototype
Production
Modeling
Surfacing
Rigging
Animation
Post-Production
Chapter 2: Concept Art and Modeling
Concept Art
References
Character Sheets
3D Modeling
Output Medium
Level of Detail and Topology
Square Is Good—Polygon Types to Use and Avoid
Alternatives to Mesh Density
Sculpting Pitfalls
UV Maps
File Referencing
Chapter 3: Rigging Concepts
An Overview of Rigging
The Basics
Nodes and Connections
Parenting
Constraints
Direct Connections
Deformers
Joints
Joint Orientation
Kinematics
Attaching Meshes to Joints
Smooth Binding
Rigid Binding
Introduction to Scripting
Scripting in Maya
MEL
The Script Editor
MEL 101
Anatomy of a Script
Saving the Script
Python
Our First Python Script—tgpGears
Creating the GUI
Querying the GUI Values
Creating the Gears
String Formatting in Python
Chapter 4: Scripting Mechanics
Engineering the Fantastic
Python’s Object-Oriented Programming
Classes in Python
Building a GUI Framework
Defining the UI Class
Adding Button Functionality
Creating tgpMechanix
Referencing the UI Class
Error Checks
Creating a Utility Section
The Connectors
Making the Spring
Assign Functionality to the Buttons
Making the Piston
And Now for a Lite Version of the GUI Framework …
Chapter 5: Rigging Mechanoids
Rigging Meep
Rigging Pre-Flight
Sketching Out the Rig
Which Rig? Bind vs. Control
Analyzing the Rig Behavior
Rigging the Legs
Placing the Leg Joints
IK/FK Leg Setup
Setting Up the Switch
Creating FK Leg Controls
Scripting tgpControlOrient
Stretchy FK Joints
Creating IK Leg Controls
Knee Controls
Stretchy IK Joints
The Condition Node
Going the Distance
Setting Up the Wings
Neck
Building the Head
Putting Together the Body
Finishing Touches
Global Scale
Chapter 6: Rigging Humanoids
Rigging Leaf
Analyzing the Bind Skeleton
To T-Pose or not to T-Pose?
Human IK Overview
Creating the Bind Skeleton
Rotate Order
Scripting tgpRotateOrder
Binding Leaf’s Mesh to the Skeleton
Smooth Bind Overview
Weight Assignment and Painting
Chapter 7: The Control Rig
The Control Rig
snapAB Script
Building the IK Leg
Automating the Limb Creation—the Limb Class
Using a Dictionary
Coding tgpLimb
Building the Spine
Hips, Shoulders …
Stretching the Spine
The Neck and Head
Building the Arms
Setting Up the Clavicles
Driven Keys
After You! No, After You—Polite Space Switching
Space Switching Using Parent Constraints
IK/FK Redux
Snappy Logic Part 1—FK to IK
Snappy Logic Part 2—IK to FK (with a dash of pole vector magic)
Finalizing the Rig
Adding Global Scale to the Rig
Cleaning Up the Channels
And …?
Chapter 8: Game On!
Exporting to Unity
Animating for Games
Prepping the Rig in Maya
Methods of Exporting Animation from Maya to Unity
Baking the Animation Keys
Exporting to the FBX Format
Importing Animation Files in Unity
Blending the Animation Cycles
Epilogue
Appendix
Index