# Compositing 3d passes and crypto
**URL:** https://forum.logik.tv/t/compositing-3d-passes-and-crypto/10479
**Category:** Flame Questions
**Tags:** 3d, aovs, cryptomatte
**Created:** [April 18, 2024, 6:30am UTC](https://forum.logik.tv/t/compositing-3d-passes-and-crypto/10479 "2024-04-18T06:30:10Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@Deepakpais](https://forum.logik.tv/u/Deepakpais)
#### Post date: [April 18, 2024, 6:30am UTC](https://forum.logik.tv/t/compositing-3d-passes-and-crypto/10479/1 "2024-04-18T06:30:10Z")
Hi everyone,
Hope you are all having a great day.
I have some 3d renders and I’m wondering in which order I composite them in action
Besides this, when I get a crypto render containing the standard crypto\_asset, crypto\_material and crypto\_object which one do I select to extract the relevant mattes? This is something new I’m dealing with. I have noticed that crypto\_object and crypto\_asset extracts each individual component of the 3d object. Crypto\_material extracts the bulk of the components in a seperate matte
These are the passes provided
Wondering about the best way to use them
beauty
crypto\_asset
crypto\_material
crypto\_object
diffuse
diffuse\_albedo
direct
dome\_lgt
indirect
key\_lgt
N (normals)
occ
P (position)
shadow\_matte
specular
Z (z depth) this is white, I can’t see any depth info
I know action has a few maps, do I add some of these passes as maps in action or use the comp node to combine them?
How do I use these passes for delighting or motion blur?
Specifically the crypto, albedo, normals, position and z depth
Thanks in advance, i know it’s a big ask but any info would be appreciated to build a proper workflow…
Have a great day ahead
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### Author:  [@PlaceYourBetts](https://forum.logik.tv/u/PlaceYourBetts)
#### Post date: [April 18, 2024, 10:56am UTC](https://forum.logik.tv/t/compositing-3d-passes-and-crypto/10479/2 "2024-04-18T10:56:04Z")
There is a lot to discuss here.
First let’s talk about render passes and specifically AOVs
Your list is initially quite daunting but in an ideal world you just need the beauty and the alpha.
A over B boom. Job done. Everything else has been provided to make you look like a wizard in front of the client. Use the rendered elements and respond to clients feedback and improve the image without needing to go back for another lengthy render.
Cryptomattes are quite unique and I would recommend you looking for more topics in Logik that discuss these further. A quick intro. Expect one preview layer that helps you to select the matte and six layers that look like RGBA but are actually quite unique and need to be used in conjunction with the cryptomatte node.
Some of your other passes look like AOVs
diffuse
diffuse\_albedo
direct
dome\_lgt
indirect
key\_lg
specular
These guys are steps that the CG render uses on its way to make the beauty. Think of them like pre comps. You should be able to use them to help refine the beauty either by subtracting them and tweaking before adding them back or if you get the correct mix you can completely rebuild the beauty yourself and tweak each element as required (not required). Find out what rendering your CG is using and then google the AOV recipe specific to that program.
N (normals)
occ
P (position)
shadow\_matte
Z (z depth)
These guys 👆 are what I like to call utility passes. Not part of the beauty rebuild but can be helpful.
Ok N normals. I like to use this for subtle relighting. You mention action maps. You need to use action and apply this as a normals pass before adding in you own lights in flames 3D compositor.
P. World P or object P. Like depth but in all three, X, Y and Z directions. Like z depth, this might not look like much but you should try and normalise the values. I like to us the 2D histogram and set my white and black values.
Happy to help you further but see how you go with this for now. Good luck 🤞
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### Author:  [@Deepakpais](https://forum.logik.tv/u/Deepakpais)
#### Post date: [April 19, 2024, 7:30am UTC](https://forum.logik.tv/t/compositing-3d-passes-and-crypto/10479/3 "2024-04-19T07:30:44Z")
Hey @PlaceYourBetts thanks for the informative reply.
Unfortunately the company I work for has decided to use DMP for the shot I’m working on.
I tried the cryptomatte in flame and it worked for another shot. For this shot the crypto passes don’t show the beauty pass, it’s black, however I can extract the mattes.
The same crypto pass in nuke displays properly with different colours for each object.
Wonder why that was happening.
I’ll explore it further
Thanks again, have a great day ahead
Cheers
Deepak
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### Author:  [@leovfx](https://forum.logik.tv/u/leovfx)
#### Post date: [April 26, 2024, 1:11pm UTC](https://forum.logik.tv/t/compositing-3d-passes-and-crypto/10479/4 "2024-04-26T13:11:06Z")
Hi Deepak,
You can plug anything into the first input of Cryptomatte as a reference image to pick from. When you pick an object, it’s not actually sampling anything from this input, it’s picking from the combination of the other inputs (at the same pixel location). I normally plug in the CG beauty pass.
These AOVs should add together to create the beauty pass (literally add them all together - add, add, add add):
diffuse
direct
indirect
specular
(on other occasions you might also have other AOVs that make up the beauty: transmission, emision, sss etc). If adding these doesn’t create the beauty then your CG artist has forgotten to render a relevant pass.
These light groups should also add together to create the beauty pass:
dome\_lgt
key\_lgt
…allowing you to adjust each one independently before adding them together.
Hope that’s helpful
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### Author:  [@Deepakpais](https://forum.logik.tv/u/Deepakpais)
#### Post date: [April 26, 2024, 1:23pm UTC](https://forum.logik.tv/t/compositing-3d-passes-and-crypto/10479/5 "2024-04-26T13:23:03Z")
Oh thanks so much @leovfx
Very informative