Introduction to Stage Setup

New in Isadora 3, Stage Setup configures video output channels, called stages. A stage receives video input from Isadora actors and renders video on its assigned displays. 

You use Stage Setup to assign displays connected to your computer to stages, blend video output across multiple displays by combining them into a single stage, and create virtual stages which are not assigned to a physical display.

Open Stage Setup by selecting Output > Stage Setup... from the menu.

You may close the Stage Setup window at any time. Changes are automatically saved and applied as they are made.

NOTE: Unlike the Stage Preferences found in prior versions of Isadora, a Stage Setup configuration is specific to an Isadora document, and is not applied globally to all files opened in Isadora 3.

Displays and Stages

Isadora features extremely flexible control of video output. You can send the same video to multiple projectors simultaneously, or show a different video on each, composite several videos together, or any combination in between. 


A display is any digital projector, screen, monitor, television set, or other video hardware connected to your computer. 

Isadora 3 can address up to 16 connected displays. However, the number of discrete displays which can be connected to your computer is also affected by your hardware specifications.


Isadora makes video output highly configurable by assigning displays to stages.

Actors and preferences refer to stages using a stage number. For example, the Projector actor uses the stage number as the value in the ‘stage’ input property to determine where it will output video.

Isadora 3 supports up to 48 stages. However, the total number of active stages your computer can support is also affected by your hardware specifications.

Multiple displays may be assigned to a single stage so that they can all be addressed as one. However, each display should only be assigned to one stage at a time. Refer to the article on “Working with Multiple Displays” for details.

Main Display

The built-in screen on a laptop computer or the monitor of a desktop system is often used for control and editing purposes, rather than video output, and appears as Display 1 (the “main display”). Isadora automatically skips using this display for stage assignments unless the maximum number of displays has been reached. You can manually assign this display to stages, but doing so may obscure your computer desktop when the stage is displayed. Remember, you can use a keyboard command to show or hide the stages (ALT + G on Windows or ⌘G).

Virtual Stages

Virtual Stages are stages without any corresponding displays. Virtual stages work exactly like a stage: it receives video and have a stage number, but there is no actual video output hardware associated with it. 

If a display is added to a Virtual Stage, it ceases to be a Virtual Stage and is instead converted into a Stage. A stage is automatically converted to a Virtual Stage if all displays are removed within it.

Assigning Displays with Stage Setup 

To assign displays to stages, choose Output > Stage Setup… from the menu along the top of your display. The Stage Setup window appears:

A new Isadora document contains a single stage (“Stage 1”) automatically assigned to “Display 2”. If there is a second display connected to your computer, the resolution is determined automatically based on the display resolution. If not, a default HD resolution is used (1920 x 1080). 

Typically, one stage is needed for each display you wish to use for video output.

Adding Additional Stages

You add additional stages by clicking the “Add a New Stage”  button found in the bottom left corner of the Stage Setup window. This new stage is added and automatically assigned the next available display.

To change which display is assigned to a Stage:

  1. Select the Stage from the Stage List.
  2. Click the “Display” in the Layout Editor to view the Display Settings:
  3. Use the “Select” drop-down menu in the bottom left corner of the Stage Setup window to specify which display you wish to use.
  4. If you have a second display output connected to your computer, the description and resolution of the display will be shown in the pop-up menu text (i.e. Screen 2 (640x480)). If not, it will just say “Display 2”.

When creating a new stage or changing an assigned display, the stage resolution is determined automatically using the resolution of the corresponding display. However, if display is not connected to your computer, the default resolution is used (1920 x 1080).

You can close the Stage Setup window at any time. Your changes are automatically saved and applied.

Stage Numbering

The order of the stage list is important! Stages are automatically numbered sequentially, starting from “1”. Drag stages within the Stage List to change the Stage Number.

NOTE: to drag, click and hold the mouse button until the cursor changes into a closed hand icon ; this slight delay is used throughout Isadora to prevent accidental drags during a show.)

Stage Preview

To see a preview of your stages:

  1. From the menu, check Output > Force Stage Preview.
  2. A floating window appears, allowing you to preview the stage output. You can move this floating window to a convenient location on your main display.

While viewing the stage preview, output to your connected displays is disabled.

Showing the Stage Output

By default, stage output is hidden on assigned displays.

To show stage output on all assigned displays:

From the menu, chose Output > Show Stages

To hide stage output on all assigned displays:

From the menu, choose Output > Hide Stages.

If a scene doesn’t have any actors rendering video (such as an active Movie Player connected to a Projector actor), the stage output will appear as video black.