Mental Ray - Custom Color pass with refracted objects?

Become a member of the CGSociety

Connect, Share, and Learn with our Large Growing CG Art Community. It's Free!

THREAD CLOSED
 
Thread Tools Search this Thread Display Modes
Old 02 February 2013   #1
Mental Ray - Custom Color pass with refracted objects?

I was watching a tutorial on vray where the guy was writing a custom color pass that had an object in a glass of water with ice cubes. He was writing each object to the R G or B channel, and then he could use those as alphas in Nuke. As expected, each object was in its respective channel, but they were also showing up in reflections/refractions. So lets say the glass/ice is the green channel, and then there is a toothpick in the glass that is assigned to the blue channel. Where the toothpick is refracted through the glass, you get yellow, because it adds the green and blue, and you can adjust each channel separately.

So far I haven't been able to achieve this in Mental Ray. Is it possible? I'm just getting a solid color for whatever object is in the foreground, but nothing showing up through refractions.
__________________
Demo Reel 2012-13!
 
Old 02 February 2013   #2
Currently mental ray renders to a matte channel whatever is in the primary ray. It's actually more of a shader limitation than anything. mental ray can render objects (occluded or not) in their entirety to a framebuffer if you wanted. (For example, a car behind a building would still get rendered completely even though it's behind something.) But the framebuffer system for now doesn't support that or the mattes through secondary rays.

It's something we'd like to see in the layering library but isn't available just yet in the Beta.
__________________
My opinions are always my own...and maybe a friend's, but never my employer's.
 
Old 02 February 2013   #3
Thread automatically closed

This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.
__________________
CGTalk Policy/Legalities
Note that as CGTalk Members, you agree to the terms and conditions of using this website.
 
Thread Closed share thread



Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
CGSociety
Society of Digital Artists
www.cgsociety.org

Powered by vBulletin
Copyright 2000 - 2006,
Jelsoft Enterprises Ltd.
Minimize Ads
Forum Jump
Miscellaneous

All times are GMT. The time now is 07:28 AM.


Powered by vBulletin
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.