The Cg Tutorial

Martin Ecker writes "NVIDIA's book The Cg Tutorial: The Definitive Guide to Programmable Real-Time Graphics, published by Addison-Wesley is a book that many 3D graphics programmers have been waiting for. Finally a book is available that introduces NVIDIA's high-level shading language Cg (short for 'C for Graphics') and the concepts involved with writing shader programs for programmable graphics pipeline architectures to the interested reader." If you are such an interested reader, you'll find the rest of Ecker's review below.

The Cg Tutorial: The Definitive Guide to Programmable Real-Time Graphics
author	Randima Fernando, Mark J. Kilgard
pages	384
publisher	Addison-Wesley Publishing
rating	8
reviewer	Martin Ecker
ISBN	0321194969
summary	An excellent introduction to the high-level shading language Cg (C for Graphics) and its uses in real-time 3D graphics.

The first half of the book teaches the basic language constructs of the Cg shading language and shows how to use them in concrete example shaders, whereas the second half concentrates on more advanced techniques that can be achieved on today's programmable GPUs with Cg, such as environment or bump mapping. Even these more advanced techniques are explained in a clear and easy-to-understand manner, but the authors do not neglect to present the mathematics behind the techniques in detail. Especially the more serious 3D programmer will appreciate this fact. The explanation of texture space bump mapping must be the easiest-to-understand explanation of the technique I have read to date, which alone makes it worth to have this book on my shelf. At this point it is important to note that the book does not discuss the Cg runtime which is used by applications to compile and upload shaders to the GPU. The book focuses exclusively on the Cg language itself. So if you're already familiar with Cg and want to learn how to use the Cg runtime, this book is not for you and you should rather read the freely available Cg Users Manual.

The book contains many diagrams and figures to illustrate the discussed equations and show the rendered images produced by the presented shaders. Note that most figures in the book are in black and white which sometimes leads to funny situations, such as in chapter 2.4.3 where the resulting image of a shader that renders a green triangle is shown. Since the figure is not in color the triangle that is supposed to be solid green ends up being solid gray. However, in the middle of the book there are sixteen pages with color plates that depict most of the important color images and also show some additional images of various applications, NVIDIA demos, and shaders written for Cg shader contests at www.cgshaders.org.

Accompanying the book on CD-ROM is an application framework that allows you to modify, compile, and run all the example shaders in the book without having to worry about setting up a 3D graphics API, such as OpenGL or Direct3D. The application framework uses configuration files to load meshes and textures and set up the graphics pipeline appropriately for the shaders. This way the Cg shaders can be examined and modified in isolation with the results being immediately visible in the render window of the application. Thanks to this framework application even readers that are not yet familiar with a 3D graphics API or even 3D artists interested in programmable shading on modern GPUs can begin to learn Cg and experiment with real-time shaders.

A final note for programmers using Direct3D 9: The high-level shading language included with the latest version of Direct3D, simply called HLSL for High-Level Shader Language, is syntactically equivalent to Cg. Everything written in the book about Cg equally applies to HLSL. Thus, the book is also an excellent guide for programmers that only intend to work with HLSL.

This book truly is the definitive guide for all beginners with the Cg language, and also more advanced 3D programmers will find the chapters about vertex skinning, environment mapping, bump mapping, and other advanced techniques interesting. Once you've started writing shaders in Cg you will never want to go back to writing them in low-level assembly shading languages ever again.

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You can purchase The Cg Tutorial: The Definitive Guide to Programmable Real-Time Graphics from bn.com. The book's official website has additional information and ordering options besides. Slashdot welcomes readers' book reviews -- to see your own review here, read the book review guidelines, then visit the submission page.

Guards, Seize Him!

[WeenisOnyatonsils]

Control makes it easier to implement standards. Standards make it easier to develop. Development makes it easier to profit. Your argument makes no sense. Of course NVIDIA is trying to control the graphics market - that's their job. If controlling the language is one of the best ways to go about doing that, why shouldn't they try? I smell a big fat commie rat.. and it's you.

Re:NVIDIA

[TheRealRamone]

Ummm... As the reviewer points out, Cg is more or less equivalent to gpu-vendor-neutral HLSL for Direct3D - which belies your comment about Nvidia trying to dominate the market with a language.

However, one might say that MS and Nvidia are doing so together...

--TRR

Re:Sounds interesting, but

[AegisKnight]

The whole point of shaders is that you can now program the video card HARDWARE, which is much faster than doing everything in software.

Re:Platform independence! .. uh..no nvidia.. ati..

[ShallowBlue]

Wrong! Cg and also the Cg runtime are programmed on top of the standardized APIs OpenGL and Dirct3D. So Cg shaders work on any HW that supports these standard APIs.
On top of that: Since it will probably take an other 200 years for OpenGL 2.0 to see the light of the world Cg is the only way to write high-level shader programs for OpenGL.