I want to make the black parts in the image below transparent, but I’m not sure how to do it. Is there a Node or NuGet package that allows setting transparency based on color, or is there a better approach?
If you want to make a mask and blend it with another texture use a Blend node!
I would suggest to do it so:
In your example, you just need to make a contrast higher, so that the gray area will be white.
Best, Anton