Character rigging is the method with which you create a system for animating a character. A rig is represented by two primary mechanics: the skeleton, consisting of hierarchical rotations to drive the motions, and a skin, or method of deforming the geometry that makes up the character model. Essential Skills in Character Rigging is a beginner’s guide to learning and understanding the essential aspects of character setup, evaluation, skeletal construction, and deformation. Borrowing from the author’s extensive experience in the field, it presents the primary theories, constructs, and objectives for constructing a basic rig from the ground up, just as it would be done in a professional studio.
The book explains the basic elements of hierarchies, skeletons, kinematics, deformation, skinning, and creating relationships between nodes. It gives hands-on experience with taking a completed character model and setting it up with a skeleton with kinematics and soft-skin deformation. It also gives specific instructions on using inverse kinematics systems, and how to set up the essential mechanics of a human rig with these systems. All of these lessons are conducted using a simplistic, conversational style that keeps technical and mathematical jargon to a minimum. The book also includes video tutorials corresponding to specific modules.
Essential Skills in Character Rigging takes aspiring character artists through the vital components in the process of taking a 3D character model and turning it into an animatable rig that is ready for production in film or games. It identifies the universal fundamentals at work behind character rigging, and the practical complexities of the process are broken down into simple steps that are easy to comprehend and execute.
Table of Contents
What Is a Hierarchy?
How Do You Make a Hierarchy in 3D?
What Does "Inheriting Transform" Mean?
What Is a Rotation?
What Are Euler Rotations?
What Is Rotation Order?
What Are Quaternion Rotations?
What Rotation Types Do I Use? Why Have Two Types of Rotations?
Joints and Joint Orient
What Is a Joint?
What Properties Do Joints Have That Other Types of Transforms Don’t?
What Is a Joint Orient?
How Do You Set Joint Orients?
What Is the Best Configuration to Set Up Joint Orients?
How Do Joint Orients Relate to Rotation Order?
Does Translating Joints Affect the Joint Orient at All?
What Is a Skeleton?
What Are Skeletons Used For?
What Is Forward Kinematics?
What Different Poses Are Characters Modeled in, and How Does That Affect the Skeleton?
What Is Skeletal Alignment and How Does it Relate to the Character Model?
How Do I Assess a Character Model for Skeletal Assignment?
Lesson 1: Creating the Basic Skeleton
Intermediate Skeleton Setup
How Do I Orient My Joints Properly? How Do I Determine Rotation Order?
When Do I Need to Customize My Joint Orients? How Do I Set Custom Joint Orients?
What Are Twist Nodes? How Do I Put Twist Nodes into My Skeleton?
What Twist Nodes Do I Need to Create for My Human Skeleton?
How Do I Insert a Twist Joint if I Need One?
Do I Have to Do All This on the Other Side?
What Is Inverse Kinematics?
Why Do I Need Inverse Kinematics?
How Do I Create IK Chains?
What’s the Difference between Single-Chain and Rotate-Plane IK? What Is a Pole Vector?
How Do I Edit IK Chains and Their Parameters?
What Are the IK Essentials for the Humanoid Body?
What Is Spline IK?
Lesson 1: Building Standard IK Chains for a Human Arm
Introduction to Deformation
What Is a Deformer? How Do Deformers Work?
What Are the Different Kinds of Deformers?
How Are Deformers Used in Modeling, Animating, and Character Rigging?
Skinning a Character
What Is Skinning?
How Does Skinning Work?
What Are the Different Types of Skinning Methods?
What Are the Important Parameters of Binding a Character?
Can I Let Maya Do My Skin Weights for Me?
What Is Artisan?
What if I Need to Move a Joint after Skinning My Character?
How Can I Save My Skin Weights So I Don’t Have to Do Them Again?
What Is Secondary and Tertiary Deformation?
Lesson 1: The Zeman Skin Weight Method
How Do You Make Relationships between One Node and Another?
Why Do You Need to Make Relationships between One Node and Another?
What Are Constraints and What Do We Use Them For?
What Are Expressions?
What Are Math Nodes?
What Are Driven Keys?
What’s the Best Method of Generating a Relationship? What Are the Differences between One Method and Another?
Lesson 1: The Reverse Foot
Lesson 2: The Pole Vector
Lesson 3: Driving Hand Poses with Driven Keys
Lesson 4: Driving Corrective Blend Shapes
Lesson 5: The Twist Rig
Nicholas B. Zeman started his career in 3D graphics at the University of Kentucky, Lexington, where during graduate school he began working at 3D Studio Max. He left Kentucky for San Diego, where he was offered a job at Red Zone Interactive, a then-small company making the NFL Gameday series for Sony Computer Entertainment. He continued working for them as an expert in character rigging, facial rigging, and facial animation after they were purchased by Sony Computer Entertainment America, until the team was disbanded and the NFL Gameday series was canceled. He was later hired by Take Two Interactive in San Rafael, where he continued to develop and manage character rigs for the NBA 2K series, All-Pro Football 2K8, MLB 2K9-10, and NHL 2K9. After almost 12 years in character rigging for sports games, he left employment as a game developer to focus on the academic pursuit of interactive development. He became a professor at Northern Kentucky University in the Media Informatics Department and began his own digital media technology company, RHZ Development LLC, where he consults and produces functional games through gamification, mobile apps, and mobile games under the studio brand Little Fish Games and RHZ Development.