[BUG] Night mode only works in legacy reprojection mode

[guysoft]

The Night Mode setting under setting under general does not work.

To Reproduce Steps to reproduce the behavior:

1. Go to SteamVR Settings
2. General
3. Top option of night mode set to On
4. VR stays not in night mode

Expected behavior Night mode should work

System Information (please complete the following information):

• Distribution: Ubuntu 21.04
• SteamVR version: 1.17.7
• Steam client version: Built Jul 20 2021 22:25:57
• Opted into Steam client beta?: No
• Graphics driver version: Nvidia 470.57.02
• Gist for SteamVR System Information: https://gist.github.com/guysoft/dd7620f11501a156e338a8ea6e3d4bb0
• Original Vive

Screenshots Not applicable

Additional context Add any other context about the problem here.

Note: Commenters who are also experiencing this issue are encouraged to include the "System Information" section in their replies.

[guysoft]

Still playing with this, It seems like the hmdDisplayColorGainB R/G/B values settings don't work neither.

[okawo80085]

Bummer, idr if this setting works on Windows, if it doesn't its probably just an echo from the past at this point :/

[guysoft]

So I booted to test.

1. It works on windows
2. Both LuxVR and OpenVR-Advanced-Settings use this to set the rgb values (related https://github.com/egemenertugrul/LuxVR/issues/1)

So this is not an old setting, its used by fairly recent applications. I think what ever isn't working on the night mode, is also not working on the RGB settings - so it would be helpful to determine why this not working.

[okawo80085]

Huh, really weird, i'll try to check if its a driver side thing or not.

[okawo80085]

OVR Advanced settings color and brightness settings work, although on Linux you need to enable "Use Overlay For Color" (an option at the bottom right of the video tab) for it to work and toggle it on near the brightness slider

[guysoft]

Ok, I managed to get the steam version working by following this issue, extracting the appimage and removing some files: https://github.com/OpenVR-Advanced-Settings/OpenVR-AdvancedSettings/issues/569#issuecomment-890587084

It seems that putting Use Overlay for color actually changes the behavior, it makes it add color rather than subtract it, which would not be what you want for night mode :-/ So now it adds more colors and does not remove the existing blue, which is what you get in windows without the color overlay option checked

[okawo80085]

OHHHHHHHHHHHH, it adding color sorta makes sense though, because the way they do it with an overlay is using a texture alpha applied over the eye view textures before displaying them to the user :/

Also is there no way to mix it with the brightness values to achieve the desired effect?

[guysoft]

I played around with it and doesn't seem to help much. I tried values from here: https://academo.org/demos/colour-temperature-relationship/ (Converting 0-255 to 0-100).

Does not seem to give the effect, it only makes stuff brighter.

[okawo80085]

Well shucks. I still have a bit of hope left tho. I need to check how the texture overlay math is done, if we're luck and it allows negative values for pixels or alpha we can pull it off, if not we'll need to look for a new solution :/

[guysoft]

Ok I found a workaround. Which might indicate where the problem is. It works per application is set to "legacy reprojection mode", night mode starts working. As soon as you leave the app that uses the setting night mode stops. Its not a good workaround because it halfs the framerate.

[okawo80085]

They changed the default reprojection mode not for nothing after all, the new one gives you more fps, the old one allows you to use night light. Ups and down, the usual. Good that there is a work around for this though.