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)

Exploring Pose::GetGlobalTransform

One of the things that makes the GetGlobalTransform function of the Pose class is that it always calculates the world transform. Consider a situation where you request the world transform of a node, then immediately after, the world transform of its parent node. The original request calculates and uses the world transform of the parent node, but as soon as the next request is made, that same transform is calculated again.

The solution to this is to add two new arrays to the Pose class. One is a vector of world space transforms and the other contains dirty flags. Any time a joint's local transform is set, the dirty flag of the joint needs to be set to true.

When a world transform is requested, the dirty flag of the transform and all its parents is checked. If there is a dirty transform in that chain, the world transform is re-calculated. If the dirty flag is not set, the cached world transform is returned.

You will not implement this...