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)

Using IK to align a character's feet to the ground

In this section, you will learn how IK can be used to modify an animation so it looks more correct. Specifically, you will learn how to use IK to stop a character's feet from going through the ground when walking over uneven surfaces.

Now that you can solve IK chains using CCD or FABRIK, let's explore how these solvers can be used. There are two common uses for IK, that is, to position hands or to position feet. In this section, you will explore what it takes to clamp a character's foot to the ground as the character is walking.

To solve foot clamping, you could check the last global position of the foot against the current global position. If the foot motion hits anything on the way, pin the foot to the ground. Even the most trivial solutions have edge cases: what happens if the up motion is too far away? At what point in the animation cycle can we interpolate between pinned and non-pinned positions?

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