Meeting Abstract
Three-dimensional motion capture based on high-speed videography is a staple technique of comparative biomechanics. Historically, the necessary equipment has been cumbersome and expensive, thus largely precluding use of the technique in natural settings, by specialists in other fields (e.g. animal behavior, ecology), and in financially restricted situations. New consumer grade equipment (e.g. sports/action cameras, DSLR’s with HD video) offers far greater portability, and resolution and recording rates comparable to systems costing ten times as much. However, consumer grade equipment lacks the ability to synchronize among multiple cameras and may introduce substantial lens distortion. We have developed a workflow based on open-source Python or MATLAB modules that addresses such problems, and that automates some steps of 3D calibration and animal tracking to reduce both analysis time and reconstruction error. We present several data sets of flying animals (various species of insects and birds) with sample volumes ranging from 0.3 m3 to over 20,000 m3. One of our example systems is based on three GoPro Hero cameras, fits in a small backpack, can record continuously for approximately an hour at 120 Hz (battery limited), and is extremely weather- and damage-resistant. Field setup and camera calibration required as little as three minutes, offering the ability to record relatively unpredictable behaviors in remote and harsh conditions. We foresee that such an affordable and intuitive setup will permit the use of 3D motion tracking across a wide range of size scales, environments, and study-areas in biology, and will bring this important technique to researchers with limited funding.
