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

Rendering geometry in WebGL


The following are the steps that we will follow in this section to render an object in WebGL:

  1. First, we will define a geometry using JavaScript arrays.

  2. Second, we will create the respective WebGL buffers.

  3. Third, we will point a vertex shader attribute to the VBO that we created in the previous step to store vertex coordinates.

  4. Finally, we will use the IBO to perform the rendering.

Defining a geometry using JavaScript arrays

Let's see what we need to do to create a trapezoid. We need two JavaScript arrays: one for the vertices and one for the indices.

As you can see from the previous screenshot, we have placed the coordinates sequentially in the vertex array and then we have indicated in the index array how these coordinates are used to draw the trapezoid. So, the first triangle is formed with the vertices having indices 0, 1, and 2; the second with the vertices having indices 1, 2, and 3; and finally, the third, with vertices having indices 2, 3, and 4. We will follow...