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

Time for action – examining the ray traced scene


  1. Open the file ch10_Raytracing.html in an HTML5 browser. You should see a scene with a simple lit, bobbing sphere like the one shown in the following screenshot:

  2. First, in order to give us a way of triggering the shader, we need to draw a full screen quad. Luckily for us, we already have a class that helps us do exactly that from the post-processing example earlier in this chapter! Since we don't have a scene to process, we're able to cut a large part of the rendering code out, and the entirety of our JavaScript drawing code becomes:

    function render(){
        gl.viewport(0, 0, c_width, c_height);
        gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);
    
        //Checks to see if the framebuffer needs to be resized to  match the canvas
        post.validateSize();
        post.bind();
    
        //Render the fullscreen quad
        post.draw();
    }
  3. That's it. The remainder of our scene will be built in the fragment shader.

  4. At the core of our shader, there are two functions...