Skilled jugglers can freely vary the rotation of their rings — spinning them fast or slow at will. This control over rotation has the potential to enrich performance expression, but because the spinning is difficult for audiences to perceive, it has rarely been exploited as a visual element.
In this research, we propose a method that uses infrared LEDs and a high-speed camera to estimate the rotation direction and speed of juggling rings in real time, and visualizes this information through video effects. The infrared LEDs attached to each ring are wirelessly controlled to light up sequentially, ring by ring. By capturing this with a high-speed camera, the system can track multiple rings simultaneously while distinguishing each one individually.
Two rings crossing in mid-air. Each ring continues to be tracked independently after the crossing.
The estimated position and rotation data for each ring are sent over a network to a visual effect generation application. Different effects can be applied to each ring, and the effects can change in response to rotation speed and direction. This allows performers to intentionally vary their rings’ rotation to create more diverse and expressive performances.