How to use a material function with a channel-packed texture?

[NilsonLima]

@anonymous_user_07ba773b

Ah, OK.

Basically what I want to be able to do is just use a material function on any arbitrary channel of a texture. I am texture packing greyscale mask textures, and wanting to do stuff with them. And I might want to use the material function with the R, G, B or A channel, it depends. If it was always consistently just the red channel, then I could easily make the material function extract just the red channel in a way similar to what you’re suggesting.

I think the only option really is to just copy-paste the contents of the material function into whichever materials I want to use it in.

You are right, usually if you are going to use a ready to use material function accepting a T2D you will need to rewrite it in order to be able to have the functionality and apply it to a packaged texture. Note that the compression used for each channel is different, so there are few possibilities on what you can put on each channel. Usual packaged texture place Roughness in the red channel, Metallic or Height in the green channel, AO in the blue channel and sometimes Height on the Alpha channel, therefore the packaged texture receive the names: RMAH (packaged in 4 channel) or RHAO (packaged in 3 channel).