Multi Display Not working after scene reload.

Questions & Answers
1

Hi,

I am facing a weird issue,
I currently have two cameras outputting to two different displays(monitors) by using multi display.

I am activating both of these displays via a script.

	Debug.Log("displays connected: " + Display.displays.Length);
	if (Display.displays.Length > 1)
        Display.displays[1].Activate();
    if (Display.displays.Length > 2)
        Display.displays[2].Activate();

Now the problem is that when ever i reload the scene, the secondary display just freezes up, whereas the primary display works as it should.

Everything works fine in the editor, but the standalone builds are messed up.

Any Solutions to that?

Kind Regards,
Saad

7

I manage to make it work by checking if the display was already activated before activate it. You see I have this script that active display like on the example in the manual:
(Display.displays.Length > 1) Display.displays[1].Activate();

But I have this script in all my scene so after I loaded the new scene it active again and it was this that cause the bug.

So I make a static bool that register if the display was activated or not before activate it…

static bool display1 = false;

void Awake () {
	if (Display.displays.Length > 1 && !display1) {
		Display.displays [1].Activate ();
		display1 = true;
	}
}

So it’s not really a bug, but having it to check by itself when we call the Activate() function to not calling it if it was already activate would be cool.

2

What do you have your game screen resolution set to? Are you manually overriding it to span the monitors or is it set to native resolution for one monitor?

3

It’s set to native resolution for each monitor.
i have two 1920 * 1080 screens,

everything works fine the first time i launch the application, but as soon as i try to reload a scene, the secondary display just shows a frozen frame from moment just before I reloaded the scene and it stays that way.

Only way to get around is to exit the application and relaunch it.

4

I am having the same problem, have you found a solution yet?

5

This is a known issue! Please kindly vote on the issue at the link below so that this can get fixed asap:

You’ll notice that if you connect 3 monitors, the 2nd monitor will suddenly start working, and the 3rd will not. In other words, there is no issue for the first n-1 monitors, but the nth monitor will not work. When the nth monitor freezes you see the residual image of the last-rendered frame from the frame buffer.

Annoyingly, this is not an issue in the current stable release - BUT the current stable release only supports multi-monitors of equal dimensions. On the other hand, the latest beta release supports monitors of different dimensions, but has this bug referenced above!

@ddsinteractive @saadminhas101 @rahleenos

6

I fixed a part of it by calling the display.Activate() only once in the first scene loaded (a Title scene) that I never reload.

Then every scene I load / reload with several cameras (I use 3) display each camera feed on each display correctly.

But there is still the last frame freeze issue on the additionnal displays when I quit the scene to load another one.
Which is an issue with a scene with only one camera (like a selection menu).
Here there is no workaround except using also 3 cameras in every scene (you can specify to an overlay canvas the display target so even for my selection menu it’s ok).

8

I messed with this for a bunch of hours and sure is a bug.

UNITY 5.5.2

Two blank scenes , with two cameras and two canvas to diferenciate each screen

and a simple multydisplay script porvided by Unity works aparently
Fine (no errors , no strange debug data , all looks fine) during runtime but
Error at build (both screens looks strangely mixed)

UNITY 2017.2.2

Works as desired