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)

Transforming points and vectors

The Transform structure can be used to move points and vectors in space. Imagine a ball bouncing up and down. The bounce of the ball is derived from the Transform structure, but how do you know where to move each vertex of the ball? You need to transform all the vertices using the Transform structure (or a matrix) to properly display the ball.

Using a transform to modify points and vectors is like combining two transforms. To transform a point, first, apply the scale, then rotation, and finally, the translation of the transform. To transform a vector, follow the same steps, but don't add the position:

  1. Implement the transformPoint function in Transform.cpp. Don't forget to add the function declaration to Transform.h:
    vec3 transformPoint(const Transform& a, const vec3& b) {
        vec3 out;
        out = a.rotation * (a.scale * b);
        out = a.position + out;
      ...