Multi Monitor

Multi-Monitor Setup

Sucrose can place a wallpaper on a single chosen display, or span one wallpaper across all displays. You configure this in the Display Preferences dialog reached from the Portal's footer toolbar — not from the Settings pages. This page explains the three display modes, how the monitor tiles pick a target screen (ScreenIndex), the per-mode sub-options, and the fact that changing any of these settings restarts the live engine.

Contents

• Opening Display Preferences
• The three display modes
• Screen mode and ScreenIndex
• Expand mode
• Duplicate mode
• Defaults
• Engine restart on change
• Application wallpapers across monitors
• See also

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Opening Display Preferences

Open the Display Preferences dialog from the footer toolbar (icon ShareScreenPerson16, command DisplayPreferencesCommand). Multi-monitor behavior is configured here; the settings are stored in Engine.json. See Portal Interface Tour for where the toolbar lives.

📷 Screenshot needed: The Display Preferences dialog showing the Screen/Expand/Duplicate radio group and the clickable monitor tiles.

The three display modes

The dialog's top radio group selects the display mode (DisplayScreenType):

Mode (UI)	Value	Meaning
Screen	PerDisplay (default)	Show the wallpaper on one chosen monitor.
Expand	SpanAcross	Stretch one wallpaper across all monitors as a single surface.
Duplicate	SameDuplicate	Show the same wallpaper on every monitor — currently disabled in the dialog (IsEnabled=false).

Screen mode and ScreenIndex

In Screen mode the dialog shows clickable monitor tiles, one per connected display. Clicking a tile selects the target monitor and stores its index in ScreenIndex — a 0-based index that is clamped to the actual number of connected screens. The wallpaper renders only on that one display.

Expand mode

In Expand mode the wallpaper spans every display. The dialog offers an ExpandScreenType radio group (values from Skylark.Enum.ExpandScreenType) to control how the single surface is laid out across the monitors; the default is Default.

Duplicate mode

Duplicate mode would show the same wallpaper on each monitor, with a DuplicateScreenType radio group (values from Skylark.Enum.DuplicateScreenType, default Default). This mode is present in the dialog but currently disabled, so it cannot be selected in current builds.

Defaults

Setting	Key (file)	Default
Display mode	DisplayScreenType (Engine)	PerDisplay
Target screen	ScreenIndex (Engine)	0
Expand layout	ExpandScreenType (Engine)	Default
Duplicate layout	DuplicateScreenType (Engine)	Default

A related global setting, Screen Layout (ScreenType, default DisplayBound), lives on Settings → Wallpaper and governs how the engine bounds the wallpaper to the display area; see Settings: Wallpaper.

Engine restart on change

Any change in Display Preferences restarts the live wallpaper engine so the new layout takes effect (respecting your performance rules — if Backgroundog has closed or paused the engine, the restart honors that state). Expect a brief flicker as the engine is swapped, the same way applying a wallpaper does.

Application wallpapers across monitors

Application-type wallpapers behave differently from the modes above. The Aurora engine launches one process instance per monitor with the wallpaper's Arguments, reparents each window behind its display, and re-applies the layout when the display configuration changes (DisplaySettingsChanged). So a game or app wallpaper effectively runs once on every screen rather than spanning a single instance.

See also

• Settings: Wallpaper
• Portal Interface Tour
• Type: Application
• Engine: Aurora
• Performance Rules
• Managing the Library