Multi-display

You can use multi-display to display up to eight different Camera views of your application on up to eight different monitors at the same time. You can use this for setups such as PC games, arcade game machines, or public display installations.

Unity supports multi-display on:

• Standalone platforms (Windows, macOS X, and Linux)
• Android (OpenGL ES and Vulkan)
• iOS

Activating multi-display support

Unity’s default display mode is one monitor only. When you run your application, you need use Display.Activate() to explicitly activate additional displays. Once you activate a display, you can’t deactivate it.

The best time to activate additional displays is when your application creates a new SceneA Scene contains the environments and menus of your game. Think of each unique Scene file as a unique level. In each Scene, you place your environments, obstacles, and decorations, essentially designing and building your game in pieces. More info
See in Glossary. A good way to do this is to attach a script component to the default Camera. Make sure you call Display.Activate() only once during startup. As a best practice, you might find it helpful to create a small initial Scene to test your script.

Example script

using UnityEngine;
using System.Collections;

public class ActivateAllDisplays : MonoBehaviour
{
    void Start ()
    {
        Debug.Log ("displays connected: " + Display.displays.Length);
            // Display.displays[0] is the primary, default display and is always ON, so start at index 1.
            // Check if additional displays are available and activate each.
    
        for (int i = 1; i < Display.displays.Length; i++)
            {
                Display.displays[i].Activate();
            }
    }
    
    void Update()
    {

    }
}

Previewing multiple displays in your Project

To preview different Camera views, follow these steps:

1. In the Camera’s InspectorA Unity window that displays information about the currently selected GameObject, asset or project settings, allowing you to inspect and edit the values. More info
   See in Glossary, select a Target Display for that Camera.

1. Make sure you’re in the Game view.

2. From the Display menu in the top-left corner, select the Display to Preview.

API support

Unity supports the following UnityEngine.Display API methods:

Controlling monitor display positions

By default, the user’s computer sorts the relative positions of its display monitors based on its x, y virtual desktop. To override this so that your application displays without any sorting, start your application from the command line and use the -multidisplay command line flag.

• Support for Vulkan on Android added in Unity 2020.1