Most software requires input from the user, in the case of the Tethered Flight Arena this user is both the researcher and the tethered animal. Whilst the researcher can interact with the software in a traditional way (mouse and keyboard) a unique solution is required to allow for the tethered animal to interact with the system.
In order to understand what the tethered animal wants to do we use a markerless pose estimation software called DeepLabCut-live to track both of its wings. The 4 points shown in the figures below are used to track 2 positions on each wing, from these positions it is possible to calculate the wing beat amplitude within a range of 0 to 180 degrees for each wing. Currently, DeepLabCut-live can update these markers more than 165 times a second and send that information into the Unity game engine. Within Unity the wing beat amplitudes are calculated and used to update the tethered animal's heading within the virtual scene.
DeepLabCut - Website Link