Interactive Graphics
Volume Number: 15
Issue Number: 9
Column Tag: Reviews
Interactive Computer Graphics
by Doug Whitmore, Santa Cruz, CA
A top-down approach with OpenGL
This article reviews the book Interactive Computer Graphics: A top-down approach
with OpenGL by Edward Angel. Interactive Computer Graphics was published by
Addison-Wesley in 1997. The publisher indicates that a second edition will be
available sometime around September of 1999.
About The Book
Interactive Computer Graphics is a book for those wanting to learn computer graphics
using OpenGL. A discussion of what this book is necessarily starts with a discussion of
what this book is not. Unlike OpenGL Programming Guide [Neider 1996](hereafter
referred to as the "Red Book"), Interactive Computer Graphics is not a comprehensive
guide to programming OpenGL. It is also not a "how to program" book. This book
assumes a solid knowledge of C and at least an exposure to basic linear algebra,
although it does offer some background math training for those who need a brush up. At
the end of the article I will offer some suggestions for supplemental reading for those
who need it.
As for what this book is, it is a guide to learning computer graphics, and to teach the
concepts, it uses OpenGL as its graphics API. The author believes that to learn graphics
programming, you must start out writing programs and continue to do so throughout
the entire learning process. Which is why, unlike most textbooks on graphics
programming, this one has you writing programs from Chapter 2, all the way through
the final chapter. This book also offers end of chapter exercises that are very
challenging and interesting. The exercises seem to be designed to force you not only to
learn the material, but to enable you to make leaps of understanding. If you complete
two or three of the exercises in each chapter, you will have a deep understanding of
computer graphics programming by the time you reach chapter 6.
Interactive Computer Graphics is 10 chapters and 3 appendices long. All of the source
code for the chapter programs are in Appendix A and are available for download via ftp.
The author intended for this book to be a text for a typical semester long computer
graphics course for advanced undergraduates or first year graduate students. I believe
that it would be useful to those with a good background in programming and basic
linear algebra and trigonometry. The book does not assume too much about the math
skills of the reader and offers much of the basic skills needed in math.
Getting The Basics
The first chapter of the book is devoted to the obligatory coverage of the history of
computer graphics as well as the formation of images on the computer screen. Chapter
2, Graphics Programming, introduces OpenGL and 2D graphics programming. It also
begins the discussion of GLUT (OpenGL Utility Toolkit), a platform independent
windowing toolkit that is available with any implementation of OpenGL. This chapter
also has the distinction of being the first graphics book to so succinctly go through the
basics of primitive types, color models, and computer representation of text. A fresh
surprise for those of us who were forced to suffer through many chapters of such
topics in other books.
Chapter 3, Input and Interaction, is where the book gets the word "interactive" in its
title. This chapter is a great introduction to user input and interaction, an important
part of modern computer graphics. For those not familiar with event based gui
programming, this chapter offers a good introduction. Readers with experience in Mac
gui programming will find themselves skimming through large parts of this chapter.
Chapter 4, Geometric Objects and Transformations, will have many readers
scrambling for their old linear algebra textbook. Though the chapter offers some math
background, those unsure of their math skills would do well to grab a book to bone up
on matrix math and trigonometry.
Chapter 5, Viewing, takes readers through the difficult process of learning viewing
and perspective transformations. This very difficult subject is presented clearly, with
excellent diagrams throughout. It saves the harshness of calculating transforms until
the later chapter on implementation. This could be seen as a fault, except that it keeps
the reader moving forward in writing programs that implement the viewing models.
This defers the detailed understanding until the reader has had a chance to get
comfortable with using the viewing models. As a TA for a computer graphics course,
this has proved to be much less painful for students, as they understood the viewing
transformations well before they were asked to implement them.
Chapter 6, Shading, delves into great detail about light and material interactions. This
is different from the other chapters and quite puzzling as many implementation details
of the former topics are left to Chapter 7. However, light and shading is a very
important part of computer graphics, and it is good to see it given a thorough
treatment, even if overly thorough.
The Extras
The final four chapters represent everything beyond the basics. Chapter 7,
Implementation, revisits the ugly details that had been glossed over in the earlier
chapters. When you have reached this chapter in the book, you have enough to
comfortably go your own way and create the next great graphics intensive program.
However, if you are one of those that wants to know the hows and whys, chapter 7 will
give them to you. From graphics pipeline to clipping and even low level algorithms, it
is all in here.
Chapter 8, Working with Models, covers every facet of modeling. With sections on
hierarchic, recursive/fractal, physical and parametric modeling, the subject is
covered thoroughly, if not as exhaustively as it could have been.
Chapter 9, Curves and Surfaces, gives a person comfortable with their math skills the
foundation for interesting modeling techniques. If your math skills are a little rusty,
expect to be lost for most of the chapter. On the opposite side, if you are looking for a
thorough reference on all curves and surfaces, you will need to look to another book.
Chapter 10, Discrete Techniques, is where everything else that doesn't fit in anywhere
else goes. With topics as diverse as texture mapping, anti-aliasing and the other
buffers in OpenGL. In "classical" computer graphics, texture mapping isn't given much
air time, and the same is true in this book. In today's world, texture mapping is as
fundamental to realism as lighting, I would have preferred to see texture mapping
handled in one of the earlier chapters. The section on alias effects is the best treatment
of the subject that I have seen in any book. It doesn't get caught up in the misguided
notion of aliasing as simple "jaggies" on text.
Conclusion
Interactive Computer Graphics: a top-down approach is an excellent book for learning
computer graphics programming with OpenGL. The emphasis on programming practice
is evident in the examples in the book as well as in the end of chapter assignments that
are all very challenging. The first six chapters covering the basics are the ticket you
need to start programming non-trivial applications using OpenGL. The final four
chapters are a good introduction to some of the more advanced concepts in
programming, but tend to lack completeness.
For many people first learning OpenGL, the Red Book is what is recommended to them.
However, the Red Book assumes that you already have a certain amount of graphics
programming knowledge. Interactive Computer Graphics teaches you that and more. I
recommend having both books, as the Red Book is an exhaustive overview of
programming with OpenGL, and this book is a great introduction to graphics
programming.
Supplemental Books and References
As promised, here is a list of books to act as supplements as well as references.
• Angel, Edward. Interactive Computer Graphics: a top-down approach with
OpenGL. Addison-Wesley, 1997.
• Egerton, P. A. and W. S. Hall. Computer Graphics: Mathematical First
Steps Prentice Hall 1998. (A great book on basic math for computer graphics
for those not feeling confident in their math skills.)
• Foley, James D., Andries van Dam, Steven K. Feiner John F. Hughes and
Richard L. Phillips. Computer Graphics, Principles and Practice, Second
Edition. Addison-Wesley, 1995. (An encyclopedic reference on computer
graphics... the bible of computer graphics.)
• Nieder, Jackie, Tom Davis and Mason Woo. The OpenGL Programming
Guide, Second Edition. Addison-Wesley, 1996. (The Red Book.)
• Rogers, David F. and J. Alan Adams. Mathematical Elements for Computer
Graphics, Second Edition. McGraw Hill, 1990.
______________________________
Doug Whitmore (aka Good Doug) is studying for his graduate degree at UC Santa
Cruz, where he is currently TA for the Computer Graphics course. He still has no idea
of what he wants to be when he grows up, so if you have any ideas, email him at
whitmore@cse.ucsc.edu or visit him on the web at
http://www.cse.ucsc.edu/~whitmore/