How to handle channel selection for custom filters?

[_Olivier_L]

Hi, I'm using a custom filter in Sampler on top of a metallic material. Regardless of how I configure my filter (with opacity output, opacity in the alpha of the basecolor, black metallic channel) I have the metalness of the base material applied to what my filter is generating. I.e. I cannot get rid of the metalness of the base layer. Any idea how I can set up my filter to prevent this?

[Ares Hovhannesyan]

I think you are asking for customizing metalic of the material. In my screenshot I have applied "Color Variation" filter on material. After choosing Metallic material in drop down list in property panel you can use custom material and apply that filter to metallic. 

[_Olivier_L]

This is not really what I am looking for, but maybe there is a connection to this. Here is my question formulated differently: is there a way to mask part of a layer (all its channels) using the opacity channel of a custom filter?

[LoryAline · Accepted solution]

Hi,
It will help to understand if you can give some screenshots of your project in 3D Sampler.
Do you want to get rid of the metallic of the base layer entirely or depending on some parameters of your custom filter? 
It will be great to show the graph of your custom filter, I think you'll need to work on how it handles the metallic input. 

[_Olivier_L · Accepted solution]

Thanks! I thought the opacity channel alone would act as a mask for other channels, but this is not the case. So now I am masking each channel individually and it works!

[LoryAline]

Happy to hear it!