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Case Study Gallery - Rhinoceros
3D Digitizing with the MicroScribe and Rhinoceros: How to Digitize an Electric Fish - by Malcolm MacIver and Mark Nelson
Our laboratory used the MicroScribe to digitize high-precision casts of a weakly electric fish. We study these organisms for basic research into the neuroscience of sensory systems. These fish are able to detect nearby objects in the dark by sensing distortions to a weak self-generated electric field. Because they use electroreceptors that cover their whole body to sense these distortions, we needed a quantitative model of the body surface for a study of how they modify their shape while acquiring sensory information about the world.
We made the casts using a silicone rubber mold and urethane, then marked up the cast of their simple knife-like body form with 15 cross-sectional curves. We used these curves and the dorsal and ventral edges of the fish to generate the model in Rhino. Full details can be found in the following articles and web resources:
MacIver, M.A., Nelson, M.E. (2000) Body modeling and model-based tracking for neuroethology. Journal of Neuroscience Methods, 95(2): 133-143.
Nelson, M.E, and MacIver, M.A. (1999) Prey capture in the weakly electric fish Apteronotus albifrons: Sensory acquisition strategies and electrosensory consequences. Journal of Experimental Biology, 202, 1195-1203.
Nelson Laboratory Home Page:
http://soma.npa.uiuc.edu/labs/nelson/
3D digitizing with the MicroScribe and Rhinoceros: How to digitize an electric fish.
http://www.itg.uiuc.edu/publications/forums/1998-12-10/index.htm
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Computer simulation of electrosensory
image formation as a black ghost knife fish (Apteronotus albifrons)
hunts for prey using its active electric sense. A false color map
on the skin indicates the change in afferent firing rate (in spikes/s)
due to the electric field perturbation caused by the prey. The backdrop
shows an experimentally measured map of the electric potential around
the fish, which polarizes the object and induces the field perturbation
on the skin. The model was created from a cast of the fish using
a MicroScribe digitizer and Rhinoceros software, and rendered in
Softimage. |
(A) Illustration of the mounting of the cast for digitizing.
(B) High resolution polygon surface model of Apteronotus albifrons, 1,540 faces total, 70 longitudinal and 22 around.
(C) Low resolution model, 90 faces total, 15 longitudinal and 6 around.
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Learn about Immersion's tutorial that covers digitizing in Rhino.
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