Shader: Adding alpha

I have a shader material which I pulled from here:, for atmospheric scattering. I am fairly new to shaders, and this is way over my head. I’m looking for a way to add an alpha layer/filter to this shader so that anything that is black, > an rgb of (20, 20, 20) is not rendered, transparent. Any shader guru’s out there with some advice?

P.S. - I’m looking to do this with the SkyFromAtmosphere shader.

Tags{“RenderType” = “Transparent”}


Tags { "RenderType"="Transparent" }


Tags { "Queue"="Transparent" "RenderType"="Transparent" }
Blend One One