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)

Reading data from textures

This section explores how animation data stored in textures can be retrieved in a shader. In this section, you will learn how to sample the texture and what sampler states should be used when sampling the texture.

Once the data is in the right format, sampling it becomes the next challenge. The glTexImage2D function expects normalized uv coordinates and returns a normalized value. On the other hand, the texelFetch function can be used to sample a texture using pixel coordinates and return the raw data at those coordinates.

The texelFetch glsl takes three arguments: a sampler, an ivec2, and an integer. ivec2 is the x and y coordinates of the pixel being sampled, in pixel space. The last integer is the mip level to use, which, for this chapter, will always be 0.

A mipmap is a chain of progressively lower resolution versions of the same image. When a mip level is scaled down, data is lost. This data loss alters the contents of the animation. Avoid...