Machine Learning panel labeling using Render Layer ID

[MrMetatron]

Another solution that might be closer to what you are trying to do: use a null material on the proxy objects. This way they won't show up in the main beauty render, but they will still show up in the Object layer color AOV.
In this case there is no need for render layers, you can save the beauty and the segmentation map in one render.

I'm not familiar with null materials. Where can I find more info on it?

[jobigoud]

Here: https://docs.otoy.com/StandaloneH_STA/S ... ht=null%20

It looks like it's not implemented in the C4D plugin but I found a different way using opacity.

Basically the idea is to set the material of the proxy objects so that it doesn't interact with light in any way during the beauty pass, so you can see through it and only see the normal geometry, but still show up in the object layer color AOV, where it will "cover" the normal geometry and be rendered in the color of your choice.

Opacity way: set the opacity of the proxy object to 0, then in the Render AOV settings, set the Info opacity threshold to 0. (See screenshot). This threshold is evaluated as "above or equal", so even with opacity 0 the proxy object will show up in the Object layer color AOV.

If this doesn't work for you, you can also set the proxy objects material this way:

Basic > Material type = Specular.
Reflection > Float = 0.0.
Index > Index = 1.0
Transmission > Float = 1.0.
Common > Fake shadows = checked.

[MrMetatron]

The last solution with the null material solved the issue with the ability to control the color so elegantly.

Thank you for your help on this, I appreciate it very much.

Cheers