Fullscreen switches resolution to maximum ignoring bUseDesktopResolutionForFullscreen flag

We are making default fullscreen mode by modifying DefaultGameUserSettings.ini according to these link

But setting

bUseDesktopResolutionForFullscreen=True
FullscreenMode=0

Always switches desktop to maximum resolution available (in our case 4k for a 4k tv) only setting FullscreenMode=1 can keep the fullscreen resolution unchanged. Is that a bug or a feature? Why true fullscreen can not be run in current desktop resolution?

All that happen in packaged game. UE. 4.14.0

1 Like

Hello Yata,

I have provided a blueprint below that I would like you to test and let me know if this provides the results that you are looking for. As a note this can be tested in New Editor Window (PIE). After following the instruction provided above using the DefaultGameUserSettings.ini method, I am not seeing the result you have describe.

Hi Rudy

can be tested in New Editor Window

I have completely strange results. If I press G at start nothing happens - i think it is expected.
If I press R, then G, My PIE new window get very strangely stretched - maybe because i have multimonitor?))
But it definitely does not enter true fullscreen mode.
But it prints correct resolution of one monitor 1920x1200

Before going fullscreen


After R, G,

As you can see window is opened far more than actual screen, and even only portion of camera view is visible (the camera position and rotation is the same on both pictures)

(I have two 1920x1200 monitors connected in a row, launching on main monitor)

On UE 4.14.1 now.

PS: And this is completely different from how it behave in packaged game

PS2: If i play it in Standalone Game - after pressing R, G nothing happens - no fullscreen mode. But after that UE stops to respond to any user input. Can not switch to it’s window.

Put my monitor to 1600x1024 https://i.gyazo.com/863beef47185fd34fee2ae64db997642.png
Run packaged project
and it is switched to 1920x1200 https://i.gyazo.com/7387fbe4ce7b729901d9d376fa34ee54.png

here is the project you can try to pack and run it by yourself

After running a few more tests I was able to reproduce this issue on our end. I have written up a report and I have submitted it to the developers for further consideration. I have also provided a link to the public tracker. Please feel free to use the link provided for future updates. Thank you for your time and information.

Link: Unreal Engine Issues and Bug Tracker (UE-39694)

Make it a great day

bUseDesktopResolutionForFullscreen has been unused by the engine for quite some time but was replaced with bUseDesktopResolution which does the exact same thing. In 4.14 a PR of mine got accepted which removed the obsolete bUseDesktopResolutionForFullscreen for good so yea use the other one.

Thanks, man, I’ll try to check this later.

This worked for me in 4.25. Thank you.