Open the file
ch10_NormalMap.htmlin an HTML5 browser.
Rotate the cube to see the effect that the normal map has on how the cube is lit. Also observe how the profile of the cube has not changed. Let's examine how this effect is achieved.
First, we need to add a new attribute to our vertex buffers. There are actually three vectors that are needed to calculate the tangent space coordinates that the lighting is calculated in: the normal, the tangent, and bitangent.
We already know what the normal represents, so let's look at the other two vectors. The tangent essentially represents the up (positive Y) vector for the texture relative to the polygon surface. Likewise, the bitangent represents the left (positive X) vector for the texture relative to the polygon surface.
We only need to provide two of the three vectors as vertex attributes, traditionally the normal and tangent. The third vector can be calculated as the cross-product of the other two in the...
WebGL Beginner's Guide
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.
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WebGL Beginner's Guide
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Table of Contents (18 chapters)
WebGL Beginner's Guide
Credits
About the Authors
Acknowledgement
About the Reviewers
www.PacktPub.com
Preface
Free Chapter
Getting Started with WebGL
Rendering Geometry
Lights!
Camera
Action
Colors, Depth Testing, and Alpha Blending
Textures
Picking
Putting It All Together
Advanced Techniques
Index
Customer Reviews