Andrew Glassner released his two-volume book “Principles of Digital Image Synthesis” to be free for download from Google Books. This book is pretty amazing in its scope and depth. Published in 1995 by Morgan-Kaufmann Press, it provides an education in almost all the key scientific and mathematical concepts used in rendering. The human vision system and color, display systems (pre-LCD, though), signal processing, sampling and reconstruction, Monte Carlo integration, energy transport, BRDFs, and much more, in 1600 pages. I turned to it for some bits of theory for our first edition. Despite its age, it is a worthwhile volume, as the underlying science and math are still valid.
Unfortunately, Google Books doesn’t quite list the book correctly and makes it hard to find both volumes when searching. So, here are the direct links:
Just hit the PDF download link in the upper right corner of each page, prove you’re not a computer, and you’ll then have each volume. You’ll want to rename the PDFs, as Google Books calls each volume the same name, Principles_of_digital_image_synthesis.pdf. Volume 1’s PDF is 12.0 MB, Volume 2’s is 17.8 MB.
Finally, to get the errata for the book, go to the author’s page about the book.
Special bonus project: I just asked Andrew Glassner if it would be OK for someone with Acrobat or other editor to put both PDFs into a single PDF, and to fold in the errata. He said that would be great, and that he could provide a bit more new errata which is not on his webpage yet. Let me know if you’re interested in doing a good deed for the graphics community and I’ll coordinate any efforts. Update: looks like we’ve got a volunteer, and so I’m hoping a new PDF version will be available in a few days.