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)

Implementing GPU skinning

You created some basic shaders in Chapter 6, Building an Abstract Renderer and OpenGL—the static.vert shader and the lit.frag shader. The static.vert shader can be used to display a static, unskinned mesh, which is loaded with the LoadMeshes function. The static.vert shader can even display a CPU skinned mesh.

Create a new file, skinned.vert. Follow these steps to implement a vertex shader that can perform matrix palette skinning. The code is very similar to the one used for static.vert; the differences are highlighted:

  1. Each vertex gets two new components—the joint indices that affect the vertex and the weight of each joint. These new components can be stored in ivec4 and vec4:
    #version 330 core
    uniform mat4 model;
    uniform mat4 view;
    uniform mat4 projection;
    in vec3 position;
    in vec3 normal;
    in vec2 texCoord;
    in vec4 weights;
    in ivec4 joints;
  2. Next, add two matrix arrays to the shader—each array is 120 in length. This length...