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 animation clips

To generate pose data at runtime, you need to be able to load animation clips. As with the rest pose, this requires a few helper functions.

The first helper function you need to implement, GetScalarValues, reads the floating-point values of a gltf accessor. This can be done with the cgltf_accessor_read_float helper function.

The next helper function, TrackFromChannel, does most of the heavy lifting. It converts a glTF animation channel into a VectorTrack or a QuaternionTrack. glTF animation channels are documented at https://github.com/KhronosGroup/glTF-Tutorials/blob/master/gltfTutorial/gltfTutorial_007_Animations.md.

The LoadAnimationClips function should return a vector of clips objects. This isn't optimal; it's done to make the loading API easier to use. If performance is a concern, consider passing the result vector as a reference.

Follow these steps to load animations from a glTF file:

  1. Implement the GetScalarValues...