2.8 Glitching on Vertex color channel filtering

Hello, could anyone confirm if this is working on their Blender version?

I pick full red, vertex paint, but this color STILL SHOWS on eevee viewport.
Say I filter red, paint red, red (vertex colors) show on viewport.
How do you filter color channels from vertex colors on eevee?
Please help.

No filter is working to get only the red painted vertex channel passed as mono color to any other fact parameter filter on eevee. Is this normal behavior?

bump. This was working on 279

Basically I need to use vertex color filtered to add onto another greyscale value. But I can´t because when I use (red) vertex color, it shows in RED on the eevee viewport even though I used the separate RGB (R being the only channel) connected to the shader… but still I get color instead of a bw value.

Just to try and figure out what’s going on, are you in solid or rendered mode, if you are in solid mode is the viewport shading set to vertex color, and if you are in rendered mode are you in object or vertex paint mode?

Also you are using the Attribute > Fac output which is already grayscale, if you want to use the Separate RGB node then you probably want to use the Attribute > Color output.

First, I vertex paint in look and dev mode. Then I switch to render mode (eevee) I get red color instead of a monochromatic channel ( R). I did use attribute color, as well, same problem.
This is why I´m asking for help, as it is common practice to separate the rgb channels (separate rgb node) and pipe it through an R channel to a ramp to later combine (multiply) it with something like ambient occlusion. I´ve done it on Max, Modo, Softimage… But I don´t know what other thing I am missing in blender…

I cannot replicate the issue you seem to have, so the only advice I can give without screenshots/.blend file is make sure you are in object mode and not vertex paint mode, when you go into rendered view.
Your shader setup seems to have nothing to do with this problem, you could check this by doing a proper render, or by disabling overlays, and seeing if the problem persists.

You are linking the Fac output (one channel) of the vertex color to a Separate RGB node that expects three channels, whereas you should link it to the Fac input of the ColorRamp directly, or, if you want to make use of the Red channel, should link the Color output of Attribute to Image input of the Separate RGB.

Video: https://streamable.com/louwo

I forgot to mention I already did that. I tried both situations. One output from the Fac(tor) and the other attempt from the Color output. Both options through the separate RGB. I just happened to only capture the Fac output picture.

Vertex paint mode (expected behavior)

Render mode (EEVEE): not expected behavior.

Vector output directly seems to work. But this is reading the complete RGB and turning it to grayscale as 1 channel. I need to draw with the red channel influencing the fac in the color ramp.

If I paint a green vertex color, and try to “separate” it on a green channel and later re-combine it to be the factor for the mix shader, it won’t work either.
Only “red vertex color” works, even though it´s unplugged.
This is why I am suspecting of a glitch.

2017 normal “common” behavior:

Are You aware that you have vertex paint overlay that you can turn off?

If you mean this, I don´t have it on.
Also, the fact to address one -specific- vertex color as masking hasn’t been addressed even though the post title mentions it…because … ¿?