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)

glTF – loading the rest pose

In this book, we will assume that a glTF file only contains one animated character. It's safe to assume that the entire hierarchy of the glTF file can be treated as the skeleton of the model. This makes loading the rest pose easy as the rest pose becomes the hierarchy in its initial configuration.

Before loading the rest pose, you need to create several helper functions. These functions are internal to the glTF loader and should not be exposed in the header file. Create a new namespace in GLTFLoader.cpp and call it GLTFHelpers. All the helper functions are created in this namespace.

Follow these steps to implement the helper functions that are needed to load the rest pose from a glTF file:

  1. First, implement a helper function to get the local transform of cgltf_node. A node can store its transform either as a matrix or as a separate position, rotation, and scale components. If the node stores its transformation as a matrix, use the...