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+---
+title: Michael Abrash's Graphics Programming Black Book, Special Edition
+author: Michael Abrash
+date: '1997-07-01'
+identifier:
+- scheme: ISBN
+  text: 1576101746
+publisher: The Coriolis Group
+category: 'Web and Software Development: Game Development,Web and Software Development:
+  Graphics and Multimedia Development'
+---
+
+# Afterword
+
+If you've followed me this far, you might agree that we've come through
+some rough country. Still, I'm of the opinion that hard-won knowledge is
+the best knowledge, not only because it sticks to you better, but also
+because winning a hard race makes it easier to win the next one.
+
+This is an unusual book in that sense: In addition to being a
+compilation of much of what I know about fast computer graphics, it is a
+journal recording some of the process by which I discovered and refined
+that knowledge. I didn't just sit down one day to write this book—I
+wrote it over a period of years and published its component parts in
+many places. It is a journal of my successes and frustrations, with side
+glances of my life as it happened along the way.
+
+And there is yet another remarkable thing about this book: You, the
+reader, helped me write it. Perhaps not you personally, but many people
+who have read my articles and columns over the years sent me notes
+asking me questions, suggesting improvements (occasionally by daring me
+to beat them at the code performance game!) or sometimes just dumping
+remarkable code into my lap. Where it seemed appropriate, I dropped in
+the code and sometimes even the words of my correspondents, and the book
+is much the richer for it.
+
+Here and there, I learned things that had nothing at all to do with fast
+graphics.
+
+For example: I'm not a doomsayer who thinks American education lags
+hopelessly behind the rest of the Western world, but now and then
+something happens that makes me wonder. Some time back, I received a
+letter from one Melvyn J. Lafitte requesting that I spend some time in
+my columns describing fast 3-D animation techniques. Melvyn hoped that I
+would be so kind as to discuss, among other things, hidden surface
+removal and perspective projection, performed in real time, of course,
+and preferably in Mode X. Sound familiar?
+
+Melvyn shared with me a hidden surface approach that he had developed.
+His technique involved defining polygon vertices in clockwise order, as
+viewed from the visible side. Then, he explained, one can use the
+cross-product equations found in any math book to determine which way
+the perpendicular to the polygon is pointing. Better yet, he pointed
+out, it's necessary to calculate only the Z component of the
+perpendicular, and only the sign of the Z component need actually be
+tested.
+
+What Melvyn described is, of course, backface removal, a key
+hidden-surface technique that I used heavily in X-Sharp. In general,
+other hidden surface techniques must be used in conjunction with
+backface removal, but backface removal is nonetheless important and
+highly efficient. Simply put, Melvyn had devised for himself one of the
+fundamental techniques of 3-D drawing.
+
+Melvyn lives in Moens, France. At the time he wrote me, Melvyn was 17
+years old. Try to imagine any American 17-year-old of your acquaintance
+inventing backface removal. Try to imagine any teenager you know even
+using the phrase "the cross-product equations found in any math book."
+Not to mention that Melvyn was able to write a highly technical letter
+in English; and if Melvyn's English was something less than flawless, it
+was perfectly understandable, and, in my experience, vastly better than
+an average, or even well-educated, American's French. Please understand,
+I believe we Americans excel in a wide variety of ways, but I worry that
+when it comes to math and foreign languages, we are becoming a nation of
+*têtes de pomme de terre*.
+
+Maybe I worry too much. If the glass is half empty, well, it's also half
+full. Plainly, something I wrote inspired Melvyn to do something that is
+wonderful, whether he realizes it or not. And it has been tremendously
+gratifying to sense in the letters I have received the same feeling of
+remarkably smart people going out there and doing amazing things just
+for the sheer unadulterated fun of it.
+
+I don't think I'm exaggerating too much (well, maybe a little) when I
+say that this sort of fun is what I live for. I'm glad to see that so
+many of you share that same passion.
+
+Good luck. Thank you for your input, your code, and all your kind words.
+Don't be afraid to attempt the impossible. Simply knowing what is
+impossible is useful knowledge—and you may well find, in the wake of
+some unexpected success, that not half of the things we call impossible
+have any right at all to wear the label.
+
+—Michael Abrash