Book Image

WebGL Beginner's Guide

Book Image

WebGL Beginner's Guide

Overview of this book

WebGL is a new web technology that brings hardware-accelerated 3D graphics to the browser without installing additional software. As WebGL is based on OpenGL and brings in a new concept of 3D graphics programming to web development, it may seem unfamiliar to even experienced Web developers.Packed with many examples, this book shows how WebGL can be easy to learn despite its unfriendly appearance. Each chapter addresses one of the important aspects of 3D graphics programming and presents different alternatives for its implementation. The topics are always associated with exercises that will allow the reader to put the concepts to the test in an immediate manner.WebGL Beginner's Guide presents a clear road map to learning WebGL. Each chapter starts with a summary of the learning goals for the chapter, followed by a detailed description of each topic. The book offers example-rich, up-to-date introductions to a wide range of essential WebGL topics, including drawing, color, texture, transformations, framebuffers, light, surfaces, geometry, and more. With each chapter, you will "level up"ù your 3D graphics programming skills. This book will become your trustworthy companion filled with the information required to develop cool-looking 3D web applications with WebGL and JavaScript.
Table of Contents (18 chapters)
WebGL Beginner's Guide
Credits
About the Authors
Acknowledgement
About the Reviewers
www.PacktPub.com
Preface
Index

Vertex transformations


Objects in a WebGL scene go through different transformations before we can see them on our screen. Each transformation is encoded by a 4x4 matrix, as we will see later. How do we multiply vertices that have three components (x,y,z) by a 4x4 matrix? The short answer is that we need to augment the cardinality of our tuples by one dimension. Each vertex then will have a fourth component called the homogenous coordinate. Let's see what they are and why they are useful.

Homogeneous coordinates

Homogeneous coordinates are a key component of any computer graphics program. Thanks to them, it is possible to represent affine transformations (rotation, scaling, shear, and translation) and projective transformations as 4x4 matrices.

In Homogeneous coordinates, vertices have four components: x, y, z, and w. The first three components are the vertex coordinates in Euclidian Space. The fourth is the perspective component. The 4-tuple (x,y,z,w) take us to a new space: The Projective...