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)

Mixing transforms

You have transforms that represent joints at two specific points in time. To make the model appear animated, you need to interpolate or mix between the transformation of these frames.

It's possible to interpolate between vectors and quaternions, the building blocks of a transform. So it's possible to interpolate between transforms as well. Instead of interpolation, this operation is typically called blend or mix. When mixing two transforms together, linearly interpolate the position, rotation, and scale of the input transforms.

Implement the mix function in Transform.cpp. Don't forget to declare the function in Transform.h:

Transform mix(const Transform& a,const Transform& b,float t){
    quat bRot = b.rotation;
    if (dot(a.rotation, bRot) < 0.0f) {
        bRot = -bRot;
    return Transform(