Book Image

Hands-On C++ Game Animation Programming

By : Gabor Szauer
Book Image

Hands-On C++ Game Animation Programming

By: Gabor Szauer

Overview of this book

Animation is one of the most important parts of any game. Modern animation systems work directly with track-driven animation and provide support for advanced techniques such as inverse kinematics (IK), blend trees, and dual quaternion skinning. This book will walk you through everything you need to get an optimized, production-ready animation system up and running, and contains all the code required to build the animation system. You’ll start by learning the basic principles, and then delve into the core topics of animation programming by building a curve-based skinned animation system. You’ll implement different skinning techniques and explore advanced animation topics such as IK, animation blending, dual quaternion skinning, and crowd rendering. The animation system you will build following this book can be easily integrated into your next game development project. The book is intended to be read from start to finish, although each chapter is self-contained and can be read independently as well. By the end of this book, you’ll have implemented a modern animation system and got to grips with optimization concepts and advanced animation techniques.
Table of Contents (17 chapters)

Interpolating quaternions

Quaternions can be interpolated in a similar fashion to vectors. Quaternion interpolation is used to animate rotation between two keyframes. Since most skeletal animation is achieved by rotating joints over time, interpolating between quaternions is going to be

a very common operation.

Neighborhood

A quaternion represents a rotation, not an orientation. Rotating from one part of a sphere to another can be achieved by one of two rotations. The rotation can take the shortest or the longest arc. Generally, having quaternions travel along the shortest arc is desirable. When interpolating between two quaternions, which path will be taken—the shortest arc or the longest?

This problem is called neighborhooding. To solve it, check the dot product of the quaternions being interpolated. If the dot product is positive, the shorter arc will be taken. If the dot product is negative, the longer arc will be taken.

If the dot product is negative, how...