emission only where the object doesn't receive light in C4D

[francois_Guinaudeau]

Hello, I am trying to adapt this shader I made in c4d to an Arnold shader. But I can't find how to make the "city light" texture that would appear only where the object isn't affected by light. It is easy in c4d with the luma texture, but i can't find how to do that with the emission in Arnold. I hope my question doesn't feel confused.. I think this screenshot explains really well what I want to do...
Thanks for your help and time !

[cdordelly09]

Hi @francois Guinaudeau! How do you control the mask with your standard rig? Maybe you can recreate it with some expresso nodes to drive the weight of the emission and other channels.

[Shawn_Kearney1]

The Utility node is set to Color Mode: Color, Shade Mode:Plastic. Make sure that the "invert" check is selected in Color Correct, and use gamma/contrast to adjust the threshold. You can control overall brightness in Clamp, though this also is useful to protect against out of range values on the emission map.

[francois_Guinaudeau]

Well thanks a lots guys ! It works like a charm!

I didn't understand the utility node until now..

[Shawn_Kearney1]

there is a c4d shader that does this, also. I can't remember what it's called off the top of my head. But you should be able to use it with a layer texture in a similar way.