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 vectors and points

Transforming points and vectors is done in the same way as multiplying matrices. In fact, the vector being transformed can be thought of as a matrix with 4 columns and 1 row. This means transforming vectors is a matter of multiplying a 4 x 4 and a 4 x 1 matrix together.

When a matrix transforms a vector, it affects both the orientation and scale of the vector. When a matrix transforms a point, it just translates the point in space. So, what's the difference between vectors and points? The w component of a vector is 0 and the W component of a point is 1. The following steps will guide you through implementing matrix-vector multiplication:

  1. To make the matrix-vector multiplication a little easier to read, you will need to once again create a macro. This macro will take the row of a matrix and perform a dot product of that row against the provided column vector. Implement the M4VD macro in mat4.cpp:
    #define M4V4D(mRow, x, y, z, w) \
     ...