Cryptomatte AOV- Layer Shader?

[BardurM]

Good day

Is there a way to get a matte/cryptomatte of a layer shader?
To aid me in post production, i would like be able to select my "Wireframe" mask - which i use in a layered shader. As you can see in the attached image.

What would be the best way to achieve some kind of easy way to extract a matte of the wire, in the AOVs - without having to do two render passes. Is it somehow possible to achieve with cryptomatte material AOV? (See example)

Thanks 🙂

[madsd]

You can use wireframe OSL shader and set a uv modifier to face.
Stick it to some practical AOV channel. I picked Emission here.

[madsd · Accepted solution]

If you for some reason want to seed different id's inject some kind of driver.
I use Object ID here, but you can also generate your own ids in DCM and you can also sort ids on wirecolor.

You can do the same thing for the actual wires. create sets like you want.

I setup an AOV write called "go" and connect it to the AOV panel, then call "go" in a custom AOV.

Note that your first id cant be ObjID 1, it has to be 2, as 1 is used for background, that will cause all items with id to be invisible, or non pickable, since id 1 is used for background as well.
So in this case the ids for the spheres are 2,3 and 4.

[BardurM]

Thank you for both of the replies/methods.

This one - using a custom AOV was the answer i was looking for.
What i did is feed the same Arnold Utility wire frame, which i use on my shader - into a "AOV Write RGB" and just plugged the Layer Shader into the Passthrough.

And doing the rest you said - by setting up a custom AOV using the AOV Write RGB.
Boom! a Wireframe AOV 😄
This will give me that extra post-production option i was looking for 😄

Thanks again