Question Switching to linear colour space has broken post processing, URP 2021.3.20f1

Hi there, I have had my project set to gamma colour space for several years now but recently decided I want to switch to linear for the better lighting accuracy. In the editor the scenes look fine with lighting enabled however when my main camera loads in with post processing the colours go mad. My first thought was to disable each post processing effect one by one to find the culprit but that has done nothing. I then disabled each render feature one by one with again no effect. I even created a new camera in the scenes with no post processing volumes added at all but checked the post processing flag on the camera and the same issue persisted. The only way to solve it is to fully disable post processing in the graphics asset which obviously is not a solution as then I loose post processing entirely. Anyone have thoughts on the culprit?

The photos atttached show one version of the camera with post proc enabled and another with it disabled.



Thanks

 

To add to this I have also noticed all of my yellows and oranges even in the UI have become a very dark red.

 

Upon even further investigation it seems as though this is not limited to just post processing on cameras, even with all post processing disabled and the main cameras looking normal (all be it without post proc) the UI is still insanely messed up colour wise. Everything just looks red and dark.

 

all your colours, having worked in gamma space for so long, will be off by miles when switched to linear. Had the same issue. Had to go through and change brightness of everything.

For fastest/easiest process, set the colour picker to HSB/HSL so you can slide just brightness/luminance. You may need to later fine tune hue and saturation, but toning up/down the brightness will be a good start.

 

Thanks for the reply, is there any reason why turning off post processing fixes a lot of this despite no individual post proc effect causing this issue?

 

In this photo for example, the colours are fine in scene view with lighting and effects enabled, if it was a colour issue would they not be bad for both?

 

If you're using colour grading in your post processing, or bloom, or anything that messes with luminance, its going to exaggerate the changes caused by switching from gamma to linear.

Also, there's a couple of specific settings in post processing that change the way colour is treated, and greatly influenced by that switch from gamma to linear. Most significant of these is Tone Mapping Mode, which after moving to Linear you should use ACES in this option.

 

Thanks for the information, looks like I am going to have to spend some time playing around with this

 

Check your particle systems especially closely after the move to linear. They're going to suffer the greatest loss of joyfulness, as they'll almost surely have benefited from their additive blends, which will be different under linear, much more muted than before. This will be the hardest thing to recover after the move to linear. Almost everything else will look better after you've corrected brightness, but additive particles will be hard work to get the pop back.