You may need to use more than 4 calibration points to calibrate the points inside of the Touch Sensor active area when:
After selecting the number of calibration points, a black screen with the selected number of calibration points will be displayed along with the instruction, "To start calibration, touch on the target until it disappears. Repeat the process for the remaining points. (Press Space to jump points)"
If any calibration targets are split between two or more screens, those calibration targets must be jumped (see below examples 1 and 2). Perform the calibration point by point as normal, until you arrive at a split calibration point, then press Space to jump it. Now you can calibrate that point and continue with the calibration. Perform this action every time a calibration point is split between 2 displays.
Example 1 – One Touch Sensor covering 2 screens
In this scenario, we have the calibration points split by the bezel of two screens.
Make sure you touch on the center of the target.
If a calibration target fails, it will reappear after about 2 seconds. The geometric calibration is successful when all targets have disappeared.