Work in Progress of Goat chewing.
Updated February 6, 2012, Harvard University.
Four Views of a 3D Representation of Goat Mastication Using XROMM and Muscle Modeling from Catherine Musinsky on Vimeo.
X-ray Reconstruction of Moving Morphology (XROMM) is a technique and a workflow using MatLab and Maya scripts that combines bi-planar x-ray videos – from two mobile fluoroscopes each with a high speed video camera attached – of an animal performing a simple stereotyped movement such as chewing or walking, with computed tomographic (CT) scans of the animal’s bones, creating an animated three-dimensional skeletal reconstruction of the movement. We applied XROMM techniques to produce an animation of the skull and mandibles of a goat while it chewed hard food. In Autodesk Maya we then modeled adductor muscles on the bone models based on serial sections. We animated the color of these muscles based on their activation patterns, by importing recordings of muscle activity, or electromyographic (EMG) data.
Condylar movement in a Pygmy Goat during Chewing from Catherine Musinsky on Vimeo.
The working-side condyle has reached the furthest posterior position at the point of maximum lateral translation of the jaw before closing in a dorsomedial direction, during which time the condyle moves slightly anteriorly during occlusion. This explains how the shearing surfaces of opposing molars are correctly aligned during occlusion; and clarifies the structure to function relationship between the long glenoid fossa in goats and their transverse jaw movements, typical of herbivores, during chewing.
Dimensional Representation of Skeletal Movement and Muscle Activity in a Pygmy Goat.
A Thesis in the Field of Information Technology
for the Degree of Master of Liberal Arts in Extension Studies
Harvard University May, 2012
home 3D reconstruction XROMM illustration video publications art and design
Catherine Musinsky
Museum of Comparative Zoology 502
Organismic and Evolutionary Biology Department
Xray Reconstruction of Moving Morphology
This is a quick Maya playblast from a project that will eventually animate EMG values as colors assigned to muscles, corresponding to the physical movement of the bones. Muscles were modeled from physical cross sections of the goat skull. Bones were derived from ct scan data and animated according to marker data digitized from high speed biplanar xray videos. Final versions will not include camera movement.