For this function in ArUco sample, aruco::estimatePoseSingleMarkers(corners, markerLength, camMatrix, distCoeffs, rvecs, tvecs);
What is the markerLength value? How do I calculate the value?
The documentation is here. https://docs.opencv.org/3.4.3/d9/d6a/group__aruco.html#ga84dd2e88f3e8c3255eb78e0f79571bd1
But I'm not sure what it means actually.