Why black/red colors in materials' monochrome preview nodes?


Sine UE4.24, I think, when you are making a material and previewing monochrome values in any node (Add, Multiply, etc…) they are now shown as red=1 and black=0. Do you know why? For me it has no sense as it is much more difficult to notice little color variations on them (and a little confusing).


As I recall, this happens when you plug a float value into an input that takes a vec3/vec4. It converts it and since a float doesn’t need all the channels, it just puts the values into the first channel (red).

Hi Arkiras,

However it didn’t happen before… why?

Anyway, I think that’s not correct:

And I’m not sure a node with a scalar-restricted input… (They are something like “flexible”). But maybe a Component Mask with only the green channeld checked?


I am assuming whatever shader they are using for the node preview is converting it to a vec3 and only filling the red channel, same as I described above.

Why’d they change this? No idea, maybe it was a bug they never bothered fixing

Thank you Akiras,

I have already reported it as a bug. Let’s see if it is.