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Amazon sent an auto-recommended of this book to me. Unlike last time, which was humorous but unrelated, I actually appreciate this one: “Temporal Coherence in Real-Time Rendering: Practical Approaches for Capitalizing on Temporal Coherence in the Domain of Real-Time Rendering,” by Daniel Scherzer.

At $81 for a 132 page book, I suspected it was a thesis reprint. Indeed it is: you can download the thesis from here. The thesis is 130 pages long, so my guess is the book form adds nothing (and subtracts $81).

So, you can download it for free now, but should you read it? Well, it is a thesis, which means it collects various papers and presents each in turn. This thesis focuses on using temporal coherence, i.e. use previous frames’ computations in various ways. It includes Daniel’s hard shadow (history buffer), soft shadow, and discrete LOD blending work, as listed here. Since it’s a thesis, the author can stretch out a bit more and cover various areas in depth. The focus is on improving image quality: hard shadows are higher resolution, soft shadows look smoother. There are limitations to his approaches, e.g., the lights are fixed in place, and objects generally should be static.

As with most theses, it also includes an extensive “previous work” section at the beginning. There is a 23 page overview of a number of shadow techniques and LOD work, explaining strengths and weaknesses. From my skim, this looks quite good; not quite all-encompassing (which is good: there are way too many shadow papers), but hitting most of the major areas of research. Let’s put it this way: if and when we write a fourth edition, I’ll certainly carefully read his categorization of various problems and think about how to integrate it into our section on shadows. His is the best recent overview of the subject that I’ve seen. He’s also the coauthor of an upcoming survey on hard shadows, not yet available for download but which I suspect is similar to his thesis’ overview.

Update: I asked Daniel about this post, he said it’s about right (and the long subtitle is indeed a Verlag decision). The book version contains an index, and different (non-copyright-protected) images. Also of interest, their upcoming STAR survey on hard shadows will be more theoretical and detailed, similar to the hard shadow section in the SIGGRAPH Asia 2009 course Casting Shadows in Real Time (which has a solid 90 pages on shadow algorithms).

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