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)

Creating a CCD solver

In this section, you will learn about and implement the CCD IK algorithm. CCD stands for Cyclic Coordinate Descent. This algorithm can be used to pose a chain of joints in a way that the last joint on the chain comes as close as possible to touching a target. You will be able to use CCD to create limb and other IK systems where a chain needs to be solved using a target point.

There are three important concepts for CCD. First, there is the goal, the point in space you are trying to touch. Next is the IK chain, which is a list of all of the joints that will need to rotate to reach the goal. Finally, there is the end effector, which is the last joint in the chain (the one that needs to touch the goal).

With a goal, chain, and end effector, the CCD algorithm in pseudocode looks like this:

// Loop through all joints in the chain in reverse, 
// starting with the joint before the end effecor
foreach joint in ikchain.reverse() {
    // Find...