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 crowd shader

To render a crowd, you will need to create a new shader. The crowd shader will have projection and view uniforms, but no model uniform. This is because all actors are drawn with the same projection and view matrices but require a unique model matrix. Instead of model matrices, the shader will have three uniform arrays: one for position, one for rotation, and one for scale.

The value that will be placed into these arrays will be an instance index – the index of the current mesh being rendered. Each vertex gets a copy of its mesh instance through a built-in glsl variable, gl_InstanceID. Each vertex will construct a model matrix using the position, rotation, and scale uniform arrays.

The inverse bind pose is like a matrix uniform array with regular skinning, but the animated pose is not. To find the animated pose, the shader will have to sample the animation texture. Since each vertex is skinned to four vertices, the animated pose has to be found...