Skip to content

Using iTrace and SmartEye with multiple screens

Jump to bottom
fisherdog1 edited this page Feb 1, 2022 · 2 revisions

Windows represents multi-screen setups in a single pixel space. For example, if two 1920x1080 screens are side by side, the top left of one screen will be pixel (0,0) and the top left of the other screen (1920,0). However, which screen is the "leftmost" in this pixel space has no bearing on the screens' physical locations.

For this reason, iTrace needs to know which Screen object, physically described in the SmartEye world model, corresponds to which Display as understood by Windows. This is done automatically based on how the screens are named in the world model:

iTrace will attempt to match physical Screens to logical Displays using one of the following rules in descending order. If a rule fails to completely map every Display and Screen, the next rule will be used. If no rule maps all screens, the configuration is invalid and the world model file must be changed to correctly reflect the tracking setup.

  1. Exact name match. Windows typically uses names like DISPLAY1.
  2. Resolution match. If using displays with all unique resolutions, this rule will correctly map them regardless of their name.
  3. Number match. If screens end with matching numbers, they will be mapped. For example, Screen1 and DISPLAY1 will be mapped as they both end in "1".

When configuring a multi-screen world model for the first time, it may be easiest to simply name them with ascending numbers and then correct any mismatches via trial and error. For example, for a three screen setup, name the Screen objects in the world model Screen1, Screen2, and Screen3 respectively. Using the Show Reticle button in iTrace, start tracking and look at each screen, ensuring the reticle appears on that screen. If the reticle appears on the wrong screen, switch the names in the world model.

On Windows, you may also use the Identify option in Display Settings to see the number of each screen.

Once a multi screen setup is established, in the event that Windows' display numbering changes, it is preferable to change the display settings instead of editing the world model file. This may prevent confusion in downstream processing, as only one world model will correspond to a given setup.

Clone this wiki locally