Linearily blending emissive?

Hey, I have a material with an emissive channel that I’m blending between a 0,0,0 and a bright emissive using a linear interpolate node.
The alpha linearly goes from 0 to 1 with a timeline in a blueprint.

However, it appears that colors/emissive don’t visually blend linearly outside the 0 - 1 range?

When my material emissive animates, it clearly goes through 3 “stages”,
1st, color quickly being applied from 0,0,0 to 1,1,0. Then it slowly gets a bit brighter as it increases in value beyond that. Then suddenly it quickly goes super bright as it has high enough value for bloom to kick in.

This means that even though it cleanly goes from 0,0,0 to e.g 100,10,0 mathematically. It looks choppy and strange when applied in game.

Is there any established way to handle emissive interpolation?

Emissive can work perfectly smooth ! pretty sure about it
can you share a screen ?

2023-02-16 14_44_45-Kiln_Mat
It’s just a lerp from 0 to my emissive, the alpha is animated through a timeline from 0 to 1 linearly over a few seconds.

I tried using a multiply instead of the lerp to treat the scalar as a strength instead, but it gave the exact same effect.

This is what i got, lerped from 0 0 0 to 60 6 0
it look pretty smooth ,
if you dont get a linear smooth thing maybe double check the curve editor of your animation? or something else in the material?

It’s harder to see with the default lighting and bloom thresholds. It’s much faster in the beginning when it’s just getting the color, than when it’s slowly getting brighter over time to my eye. But I guess that’s just the nature of making visual sense of what is brighter than 1 which is already white, and however bloom is set to handle that.

I might just have to play with curves to make it behave with my post processing.

aaaa you were worried about the ““threshold”” difference between 0 -1 and 1 to 40 !
Yes since the value of 0 is black and 1 is already a full color, you get some kind of difference in the perceived amount of color,
pretty tricky to feel happy with cgi XD

1 Like