Simple compositing question

Become a member of the CGSociety

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

Thread Tools Search this Thread Display Modes
  10 October 2012
Simple compositing question

Hello. I am new to composting, but I understand the interface, and generally how Nuke works. I have looked high, and low on how to composite these passes, but I have had no luck.
I have a few scenes that i have rendered out of Maya with Vray, with the exr(multichannel) image format. The Passes that I have rendered out are, diffuse, GI, Lighting, Specualr, and Zdepth. Where I am running into trouble, is how do I get the channels arranged, in a way where i can look at them in the viewer, and the image looks like the beauty image, but I have the control to tweak the elements separately. I understand using the shuffle node to seperate the different channels, but I do not know the order in which to merge them, What shouldd go in the background, and then I am confused the operation that should be used. I have tried a few other methods, but I have not had any success.

Should I be using more render elements? My scene is pretty big, and I did not want to render out an ambient occlusion pass, is it necessary to get a successful composite? I am learning all of this by myself, so any help is appreciated. Thanks!
  10 October 2012
With Blender's render passes, I have to add the glossy to the diffuse, so that may be what's needed here. Not sure about the lighting passes but I assume they would be combined on top of the color passes with either an add or screen operation. GI might be either a multiply or add/screen. Z-depth is used to create atmospheric effects so it may not be needed to replicate the beauty render.
"For what is a man profited if he gains the whole world but loses his own soul?"

- Jesus
  10 October 2012
in this thread i posted some links to tutorials on vray passes:
  10 October 2012
Hey Bigwil357,

There are a few ways to separate the channels. The one I usually use is by shuffling out the channels with a shuffle node (as you pointed out).

To bring them back together I use merge nodes.

For example if you have DIFFUSE, SPECULAR, REFLECTION you merge DIFFUSE and SPECULAR with a plus operation, being DIFFUSE B and SPECULAR A.

After that you merge the former merge with REFLECTION but through a Multiply operation so that you can link to a copy operation (alpha-alpha), that is linked from the source material to this new merge. If you didn't pull the alpha back in, the source footage would come out "ghostly".

Connect to this copy node to the background footage with a merge and you are ready.

P.S - I just noticed i made a bit confusion out of this, so if you need any more help, just let me know.
Facebook page dedicated to short films! -

Last edited by Xistel : 10 October 2012 at 10:38 PM.
  10 October 2012
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
Society of Digital Artists

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

All times are GMT. The time now is 03:49 AM.

Powered by vBulletin
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.