Schematic of the processes of 3D stereoscopic imaging and its application to the analysis of shimmering waves in Giant honeybees. From top to bottom: The experimental nest was captured by two frame-locked video cameras positioned at an angle of 30° two metres in front of the nest. In the offline data assessment phase, the acquired images were processed as follows: Segmentation distinguished single agent bees in the densely packed clusters of bees on the surface of the nest; stereo matching identified corresponding agent bees in both paired images. These two processes enabled stereo tracking of the agents in subsequent frames throughout whole film scenes and triangulation of their thoracic positions regarding the three dimensions of space (x,y,z). Following the stereoscopic process, the images are evaluated. For example, the arrival of the wave front at an individual agent can be recognized by a movement detection algorithm also producing a measure for the response strength RS of the agent. This allows synchronization and pooling of 3D data (Δx, Δy, Δz) of wave "episodes" (for definition, see text) of individual agent bees at different positions of the nest for a variety of behavioural applications. The bright-grey flow charts address the stereoscopic single-agent analysis from segmentation to categorization, the dark-grey flow charts refer to further processing such as synchronization and pooling of single-agent data. The arrows and dashed lines at the right symbolize that the stereoscopic process produced further data for hundreds of agent bees simultaneously. The panels to the left of the flow charts illustrate the results of the processes shown to their right (see referenced figures and movies for details).