LED Stage Synchronization

Before presenting content on an LED stage with AR-51, you may want to synchronize AR-51’s coordinate system with the LED system.

This ensures a consistent origin across sessions and allows direct alignment with LED walls or floors.

Table of contents

1. Motivation
2. Projecting the Checkerboard
3. Rescaling the Checkerboard
4. Handling Coordinate Offsets

Motivation

You want to present something on the LED stage and synchronize AR-51 with another system.
Examples include:

• Use your body to control the content that is displayed on the LED wall/floor.
• Ensuring the AR-51 origin is placed consistently in the same spot each time.

Projecting the Checkerboard

To sync AR-51 coordinates with the LED stage:
CalibrationBoard With Colors.png

1. Project the provided checkerboard image onto the LED floor.
   • Download the checkerboard image
   • The small mark at the center of the checkerboard indicates the AR-51 origin.
2. AR-51 uses a right-hand coordinate system where Y is up.

Rescaling the Checkerboard

• You may rescale the checkerboard, but it must be uniform so that each square remains a square.
• In the AR-51 server settings:
  • Navigate to:
    Camera Calibration Settings → Checker Board Settings → Aruco Board Square Size Meters
  • Enter the real-world size of a checker square (in meters).

Handling Coordinate Offsets

If the LED coordinate system is not centered on the stage (e.g., origin is in the upper-right corner), you can adjust using:

• Camera Calibration Settings → Calibration Checkerboard Offset
• Set the offset values so AR-51 matches the LED system’s origin.