OpenKneeboard-Viewer.exe is a program included in the ‘remote control’ zip shows the images that OpenKneeboard sends to other programs, such as games. It is primarily intended for debugging, but can also be useful for capturing a 2D version of the kneeboard for streaming.

Keyboard Shortcuts

  • B: Borderless mode - no window border or title bar
  • I: show information, such as frame counter and layer (view)
  • 1-9: show the nth layer (view).
  • S: Streamer Mode
  • F: Switch background Fill: magenta, checkerboard, Windows default.
  • V: Toggle between mirroring VR and non-VR content

Graphics API

OpenKneeboard-Viewer can be launched with -G D3D11, -G D3D12, or -G Vulkan; this is a developer tool for debugging.

Streamer Mode

This switches the background color to solid magenta, and disables the error message that is usually shown when OpenKneeboard isn’t running or the kneeboard is hidden.

Recommended usage with OBS:

  1. Add a ‘Window Capture’ source
  2. Set ‘Capture Method’ to ‘Windows 10 (1903 and up)’
  3. Tick the ‘Client Area’ box
  4. Add a ‘Color Key’ filter with color set to magenta, and similarity and smoothness both set to 1
  5. Right click on the source and select ‘Scale Filtering’ -> ‘Point’

If you use two kneeboards, you will want to run and capture two copies of the viewer; in the second one, press the 2 key to switch it to showing the other kneeboard.