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billrobertson42
02-21-2007, 05:28 AM
I have been looking w/o success for a bit of detail on how to split and dice geometry for the creation of micropolygons in a reyes renderer.

I have looked at the code for several open source renderers, and I feel that I don't have enough grounding in the subject matter to get as much out of it as I should.

I have read the siggraph 2000 notes, and the '87 reyes paper on pixar's site, and while these were helpful in getting the bird's eye view of what's going on, I'm getting lost in some of the details. (I do plan to read them again).

I also noticed that it was splitting more than just geometry. The code that I was looking at (jrman -- it seems to be the smallest functional reyes renderer out there with source, that's why I picked it to start) splits uv's, normals, and other things that I couldn't quite make out.

If you know of any articles that discuss the process at a bit higher level, and then get into the math a bit I would appreciate it. Or, if you think that the best answer is to keep at the code then I'd like to know that too.

Thanks. :thumbsup:

*edit* oh, BTW, hats off to the folks responsible for aqsis, jrman and pixie for providing really nice renderers complete with code. Thanks!

djwarder
02-21-2007, 03:40 PM
Hmmm, dunno. Was thinking you could ask on Pixar's forum, but not sure if you'll get anything there. What about about asking on the comp.graphics newsgroup (http://groups.google.com/group/comp.graphics.algorithms/topics)?

Also, you could look into 2 books I've read that might be of use :

http://www.amazon.com/Production-Rendering-Ian-Stephenson/dp/1852338210/sr=8-1/qid=1172072359/ref=pd_bbs_sr_1/102-9132580-3402510?ie=UTF8&s=books
http://www.amazon.com/Physically-Based-Rendering-Implementation-Interactive/dp/012553180X/sr=1-1/qid=1172072403/ref=sr_1_1/102-9132580-3402510?ie=UTF8&s=books


Oh, and just found a REYES article with source:
http://www.adrianandsusan.dsl.pipex.com/reyes/reyes.html

Hope that helps?

billrobertson42
02-21-2007, 05:16 PM
Since the code there is experimental, it might be easier to digest (smaller, less features). I'll take a look at that. I have also seen hints that Production Rendering might have more detail. I'll take a look.

I've poked around a little on Pixar's forum, but it is mostly aimed at their customers. Although there could be a gem of a thread that I missed.

Thanks.

billrobertson42
02-21-2007, 10:34 PM
So I spent some time reading the samples of Production Renderering on google.

http://books.google.com/books?id=krTfLA5b940C&pg=PA1&lpg=PA1&dq=%22production+rendering%22&source=web&ots=a3QEeMI7id&sig=mIR4hrTl7tGK6t6m5k8yQJw2VD0#PRA2-PA299,M1

It looks like what I want for sure.

djwarder
02-23-2007, 09:44 AM
Yep, it is quite comprehensive and covers a lot of useful stuff. Thinking about it, I think the 'Physcially Based Rendering' book is more a look a raytracing and GI rather than REYES architecture, so I think the 'Production Rendering' book is definately the way to go ...

billrobertson42
02-23-2007, 06:44 PM
I got the same impression from reading earlier threads here too. Seeing that preview of Production Rendering was great though.

Thanks again.

mago
02-23-2007, 10:57 PM
I also noticed that it was splitting more than just geometry. The code that I was looking at (jrman -- it seems to be the smallest functional reyes renderer out there with source, that's why I picked it to start) splits uv's, normals, and other things that I couldn't quite make out.


The minimum that needs to be diced are:
- "P" surface position
- "N" normals
- "u" and "v" (so you can have stuff such a "dPdu" and "dpdv")
you might also need "s" and "t" for texturing.

Then, you need to dice all other parameters used by the shaders. And a shader can have many parameters. The current release of jrMan (version 0.4, released a couple of days ago) dices many parameters, but it still doesn't dice everything it should in order to support all programmable shaders :)

billrobertson42
02-25-2007, 03:20 AM
Yes that makes a lot of sense. Thank you.

Also, congratulations on the new version. I had no idea that you were working on one. This is exciting!

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