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

Configuring some WebGL properties


Here we set the background color and the depth test properties as follows:

gl.clearColor(0.3,0.3,0.3, 1.0);
gl.clearDepth(1.0);
gl.enable(gl.DEPTH_TEST);
gl.depthFunc(gl.LEQUAL);

Setting up the camera

The camera variable needs to be global so we can access it later on from the GUI functions that we will write. For instance, we want to be able to click on a button (different function in the code) and use the camera variable to update the camera position:

camera = new Camera(CAMERA_ORBITING_TYPE);
camera.goHome([0,0,7]);
camera.setFocus([0.0,0.0,0.0]);
camera.setAzimuth(25);
camera.setElevation(-30);

The azimuth and elevation of the camera are relative to the negative z-axis, which will be the default pose if you do not specify any other. An azimuth of 25 degrees and elevation of -30 degrees will give you a nice initial angle to see the cars. However, you can set any combination that you prefer as the default pose in here.

Here we make sure that the camera's rendering...