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Secondary rays and global illumination

Posted: Tue Mar 04, 2008 3:14 am
by mvanderzee
Hey there,
I was hoping someone could give me a better understanding of the attributes "Hidden to secondary rays" and "hidden to global illumination" that are under the Maxwell Render section of every maya object node.

i generally understand what GI is, and so i was wondering for what reason someone would want to hide something from GI (other than to have unrealistic lighting effects?) i read something in some other post that hiding an emitter surface from GI might serve some purpose. maybe speed of render?

And hiding from secondary rays - why would someone need to do that? is it again a performance thing?

thanks,
mv

Posted: Tue Mar 04, 2008 3:13 pm
by Jorge Alix
There is an explanation in the manual and in Maya plugin manual.
http://www.maxwellrender.com/index.php? ... guide.html
I hope this help

Posted: Tue Mar 04, 2008 5:10 pm
by mvanderzee
Cool, thanks for the response. I guess I was wondering what practical reasons one might have for hiding something from GI or secondary rays. for example, does it save substantial rendering time to hide emitters (or other objects) from GI?

just looking for ways to decrease render time!

thanks
-mv

Posted: Tue Mar 04, 2008 7:07 pm
by Mihai
I don't think hiding emitters from secondary GI will help decrease render time. These options are there mostly to help with compositing.

Posted: Tue Mar 04, 2008 7:12 pm
by Jorge Alix
These options can decrease render time but not to much.
This options are only for hide lights or reflections to help in composition tasks.

Posted: Tue Mar 04, 2008 8:55 pm
by mvanderzee
cool - thanks guys for your help!