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.

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.

Comments

Sounds interesting, but

[0x00000dcc]

Excuse my ignorace in this realm, but why would you want to want to learn Cg when you could extend a C/C++ library to include the various graphics that you want to use?

Seriously, I really would like someone to debunk this idea if possible, because I have picked up an interest in graphics programming and am just starting out - would like to know more. It seems like an easier / pragmatic route (due to code reusability) to go the other route ...

Re:Sounds interesting, but

[Molt]

Cg is a very specific language which runs on the graphics card itself, and is only used for pixel and vertex shader programming. It's always used in conjunction with one (Or even more) higher level libraries.
Firstly you have the application-level library (SDL, for example), this handles the stuff like opening windows, the user interaction. This is also the bit that's often written specifically for the game.
At the next level we have the 3d library, normally OpenGL or DirectX. This handles most of the actual graphics work itself, such as displaying your polygon meshes, applying standard lighting effects, and so forth.
Finally we hit the shader level. It's here that Cg comes into it's own, with special snippets of Cg code to get the reflections on the water to look just right and ripple as the character walks through, or to make the velvet curtains actually have the distinctive sheen. Special effects work only.
It is worth noting that Direct X does have it's own way of doing shaders now, and OpenGL does have a specification for them but last time I looked no one had this implemented.
Hope this makes sense.

good book

[Horny Smurf]

I got a copy last month, and I've only read a few chapters, and skimmed some others, but it looks liek a good book.

Don't let the title foo you -- it contains high level descriptions of the algorithms as well as the mathematical concepts. They cover some advanced realtime techniques that older books don't (since the processing power wasn't there even 4 years ago), but also discuss optimizing for low-end systems.

I do recommend this book if you ahve any interest in graphic programming (whether you use Cg or not). If you use it with Coputer Graphics (3rd edition), you should have access to pretty much all graphic algorithms. (at least until TAOP volume 7: Computer Graphics is written :)

Re:Other books/sources

[magic]

Why not a good GL wrapper for CG, does one exist? How about some good GL samples, period? Can anyone help here?

I released 75,000 lines of C++ code for supporting OpenGL game development on Windows and Linux as the G3D library. It is under the BSD license. The next release includes support for the shaders that are compiled by Cg-- you can grab it from the SourceForge CVS site.

G3D includes some small OpenGL demos (~200 lines), wrappers for the nasty parts of OpenGL, and wrappers for objects like textures and vertex shaders.

-m