High-Speed Surface Reconstruction of Flying Birds Using Structured Light

TLDR: A custom 3D surface reconstruction method is developed, which uses a high-speed camera to identify spatially encoded binary striped patterns that are projected on a flying bird to analyze wing geometry and aerodynamic variables time-resolved.

Abstract: ABSTRACT Birds fly effectively and maneuver nimbly by dynamically changing the shape of their wings during each wingbeat. These shape changes have yet to be quantified automatically at high temporal and spatial resolution. Therefore, we developed a custom 3D surface reconstruction method, which uses a high-speed camera to identify spatially encoded binary striped patterns that are projected on a flying bird. This non-invasive structured-light method allows automated 3D reconstruction of each stand-alone frame and can be extended to multiple views. We demonstrate this new technique by automatically reconstructing the dorsal surface of a parrotlet wing at 3200 frames s−1 during flapping flight. From this shape we analyze key parameters such as wing twist and angle of attack distribution. While our binary ‘single-shot’ algorithm is demonstrated by quantifying dynamic shape changes of a flying bird, it is generally applicable to moving animals, plants and deforming objects. Summary: Demonstration of a new high-speed structured-light technique that can automatically record the 3D surface of a bird taking off to analyze wing geometry and aerodynamic variables time-resolved.