Using Unity Content ​

Unity developers should make note of the following suggestions:

• Projects should be built to target Linux (x86-64). You may need to install the Linux build target using the Unity Hub installer.
• Under Player Settings / Resolution and Presentation / Resolution, select Fullscreen Mode = Fullscreen Window or Windowed.
• Under Player Settings / Resolution and Presentation / Standalone Player Options, make sure Resizable Window is checked. This will prevent Unity from fighting the window manager when it tries to place its window according to your project's configuration.

The easiest way to use compiled Unity programs in your project is to use the unity helper function when defining processes in your profile script.

Logging ​

When launched with the process helper any log output that your program emits using the Debug.Log method and similar methods will be captured in the system logs and will be viewable in the web console.

V-Sync ​

It is generally recommended to configure your project to synchronize to VBlank using the Project Settings / Quality / VSync Count setting. When this option is set to "Don't Sync" it can result in excessive CPU and GPU usage as Unity renders frames that will never be displayed. By default, newly created projects have this option set appropriately.

Transparency ​

When using the built-in Unity renderer, transparency is supported to allow a Unity program to act as an overlay or to be combined with content from other programs. When using a transparent window, ensure that your main rendering camera is configured to use a solid clear color with zero opacity.

When attempting to use transparency with a scriptable rendering pipeline, the pipeline must be configured or modified to write proper alpha channel values to the rendering surface.

Multiple Displays ​

Unity has built-in support for up to 8 full-screen windows as described here. However, since output and view layouts are entirely under the control of the compositor, Unity is merely able to suggest a preferred display. It is up to your script to decide whether or not to honor the request by inspecting the result of the preferred_output method for each surface. The default implementation of the arrange_views callback method respects this value when possible.

Unity refers to displays by index (with zero being the "primary" display) while isotope refers to outputs by connector name and has no concept of a primary output. This can make it difficult to predict which physical display corresponds to which display index in Unity. This shortcoming is especially noticeable when outputs are added or removed on the fly: the index of a particular physical display may change. Worse, Unity queries display information once on startup and does not refresh this information when displays are added or removed. To work around this, you may modify your profile script to add outputs to the layout via the place method in the order you want Unity to see them.

Finally, if the display that Unity considers the "primary" display is removed, then the Unity program will stop running (and may be re-launched by isotope with a new primary display). This can occur even if the compositor is not displaying the Unity content on that display. If you need to work around this particular problem, you may try launching Unity with the X11 flag.

It is important to keep these limitations in mind when designing Unity programs that make use of multiple displays, and avoid adding or removing displays while your project is running. The display indexes will remain stable between reboots provided they are all active on startup.

One possible workaround is to combine multiple displays into one by configuring your scene to render multiple cameras into a single viewport (a.k.a, a "split screen" mode) and then use viewportals to consistently position the individual regions on separate outputs. Another option is to have your profile script create virtual displays for Unity to use (by adding them to the layout before any physical displays) and then map any actual physical displays to the appropriate locations. Even if a physical display is unplugged, the virtual outputs will remain in the same order.

Audio Devices ​

There is a bug in all Unity versions where Unity will send audio to the first audio device it finds instead of the default audio device. This issue is reportedly slated to be fixed in the 2023.3 LTS release and may be tracked here.

For testing purposes, one workaround is to open the web console, select a different audio device, and then select the desired audio device again. Unity audio should start coming out of the desired device. Because this workaround requires manual intervention, it is only suitable for testing purposes.

A more permanent workaround is to simply disable all audio devices except the desired one, after which Unity has no choice but to use the desired device. Your system administrator may use the force-single-audio-device configuration option to implement this workaround.