Tearing when playing in Fullscreen mode

Development Programming & Scripting
1

Hello,

after setting the desired resolution and fullscreen mode to EWindowMode::Type::Fullscreen I experience tearing in the packaged build, as well as in the standalone game.

void ATDGGameMode::StartPlay() //Called at the start of the level
{
	Super::StartPlay();

	if(!GEngine || !GEngine->GetGameUserSettings())
	    	return;

	UGameUserSettings* GameSettings = GEngine->GetGameUserSettings();

	GameSettings->SetScreenResolution(FIntPoint(1920, 1080));
	GameSettings->SetFullscreenMode(EWindowMode::Type::Fullscreen);
	GameSettings->ApplySettings(false);
}

The tearing goes away if i exit fullscreen mode. Setting the fullscreen mode to either EWindowMode::Type::Windowed or EWindowMode::Type::WindowedFullscreen also produces no tearing.

Any help with solving this issue would be greatly appreciated.

Video of the tearing: https://www.youtube.com/watch?v=h5su-2WJ2lc

Minimal project reproducing the issue(zip): https://www.dropbox.com/sh/odxsk1t73b5ilwb/AABWxtix9ExKiIZC5TtGst2za?dl=0

GPU: RX 580, 4GB, i don’t think this is a driver issue because i have confirmed the tearing on another computer.

Best regards,
Penzich

2

So apparently setting vsync to true completely solves the tearing issue. Still no idea as to why i don’t need vsync when not in fullscreen mode.

	GameSettings->SetVSyncEnabled(true);