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)

Look rotation

Given a direction and a reference for which way is up, it's possible to create a quaternion that looks in that direction with the correct orientation. This function will be called lookRotation—not lookAt, to avoid any confusion with the matrix lookAt function.

To implement the lookRotation function, find a quaternion that rotates to the desired direction. To do this, create a quaternion between the world forward vector (0, 0, 1) and the desired direction. This quaternion will rotate to the right target, but with no regard for what direction up might be.

To correct the up direction of this quaternion, you first have to find a vector that is perpendicular to the current forward direction and the desired up direction. This can be done by taking the cross product of the two vectors.

The result of this cross product will be used to construct three orthogonal vectors—the forward vector, this new vector, and a vector that points up. The one you just...