GATESY, S.M.: Dinosaur Feet, Pigeon Wings, and 3-D Animation: Entertaining Science?

Software developed for the entertainment industry is a valuable resource for biologists and paleontologists interested in studying motion. Despite rather steep learning curves, high-end packages contain tools ideally suited for modeling organic structures, controlling articulated elements, importing video/film sequences, and running dynamic simulations. My lab has been using Studio and Maya software from Alias|Wavefront to approach the morphological, spatial, and temporal complexity of limb movement during locomotion. One project involves reconstructing foot kinematics in 210 million year old dinosaurs based on fossil trackways from Greenland. Many of the tracks were made by theropods sinking to considerable depth, thereby causing the substrate to intercept and preserve foot movements in 3-D. Tracks are simulated using a NURBS model foot skeleton, which emits particles as it passes through a volume of “sediment” of variable depth. Reconstructed stance phase movements are then modified to produce tracks matching the fossil data. A second project focuses on bird flight. Accurate measurement of wing joint angles has remained elusive due to the 3-D complexity of the wingbeat cycle. By rotoscoping a NURBS model pigeon over frames of high-speed X-ray film, skeletal motion can be simultaneously animated and quantified. This methodology allows a wing’s real (rather than “realistic”) motion to be analyzed at an unprecedented level of resolution, yielding both animations and data. Supported by NSF, Brown University, and Alias|Wavefront.