When I wrote Essential RenderMan fast in 2002 it didn’t seem that I was writing about a moving target. The RenderMan API is a standard, and hence doesn’t change radically from release to release. However, once you start writing things down they seem to change far more quickly than you expect.
No sooner had the book gone to press than two important renderers disappeared— BMRT and Entropy were both withdrawn as Exluna became a part of Nvidia. While these systems are missed, new comers Aqsis and 3DLight have both grown in strength and popularity (and have contributed images to this new edition), providing many users with their first experiences of RenderMan.
Global Illumination is the biggest technical development. In 2002, GI was still largely missing from the RenderMan API. Some renderers supported it, but in varying degrees and with different APIs. Pixar’s inclusion of GI in PRMan 11 announced that GI was ready for feature film production, and provided a standard interface which other implementations could maintain compatability with. Four years later and GI is almost a standard feature of RenderMan, and can be included in this second edition. I say almost as things are still changing—Integrating GI with SL shaders is a tricky job, and we are still learning how to do it. Each new release of a renderer adds some extension which may be more widely adopted, or may fade away when we realise it isn’t such a good idea after all.
The biggest change in the new edition is therefore the addition of a chapter on GI. It can only consider the core features of RenderMan GI, as each implementation still has its own unique quirks, but should provide a starting point for your own GI experiments. Everything else has been tweaked, edited and re-rendered, with extra tips, tricks, and warnings to help you through your first weeks of RenderMan. Thanks to all of those who provided images for the new edition, and to everyone at Pixar, Sitex Graphics (Scott—Who got married), DotC Software (Rick and Cheryl—Who became grandparents), Aqsis (Paul), 3DLight (Aghiles and crew), and ART for getting the software out there so that I can write about it. Thanks to everyone at the NCCA, including John Vince (who retired).
Special thanks to Amanda (who got married to me!). By the time you read this we will also be parents . . . I guess a lot does change in four years.