Computer-Generated Animal Model Stimuli

Summary

Computer-generated stimuli using the Jacky dragon as a model.

Abstract

Communication between animals is diverse and complex. Animals may communicate using auditory, seismic, chemosensory, electrical, or visual signals. In particular, understanding the constraints on visual signal design for communication has been of great interest. Traditional methods for investigating animal interactions have used basic observational techniques, staged encounters, or physical manipulation of morphology. Less intrusive methods have tried to simulate conspecifics using crude playback tools, such as mirrors, still images, or models. As technology has become more advanced, video playback has emerged as another tool in which to examine visual communication (Rosenthal, 2000). However, to move one step further, the application of computer-animation now allows researchers to specifically isolate critical components necessary to elicit social responses from conspecifics, and manipulate these features to control interactions. Here, I provide detail on how to create an animation using the Jacky dragon as a model, but this process may be adaptable for other species. In building the animation, I elected to use Lightwave 3D to alter object morphology, add texture, install bones, and provide comparable weight shading that prevents exaggerated movement. The animation is then matched to select motor patterns to replicate critical movement features. Finally, the sequence must rendered into an individual clip for presentation. Although there are other adaptable techniques, this particular method had been demonstrated to be effective in eliciting both conspicuous and social responses in staged interactions.

Protocol

Animation Design

Object Scan

Acquire taxidermic lizard. Scan the model with a Konica Minolta VI-9i. It produces a 3D object (*.lwo and *.obj files) in a single polygon mesh of 50,000 polygons. Lightwave® v8.3 has two programs used for 3D animation: Modeller and Layout. Lightwave® Modeller designs and manipulates the object. Lightwave® Layout program creates animation scenes. Lightwave® Modeller and Layout have three dimensions of positioning, orientation, and rotation: heading (Y), pitch (X), and bank (Z).

Texture Acquisition

Photograph a live liza....

Discussion

Computer-generated animations are increasingly becoming a popular tool in which to investigate questions regarding communication in animal behaviour. By using animation techniques, researchers can focus on specific aspects of signal design, and manipulate features that previously were unable to be investigated due to limited technology. Although conventional staged animal encounters still demonstrate theoretical principles, animation techniques now provide a sophisticated tool for examining more detailed interactions.

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Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
New Item	Digital camera	Konica Minolta Holdings, Inc.	VI-9i	Used to acquire 3D mesh (done by New Dawn® - Bexley North, NSW Australia)
Lightwave® 3D	Software program	NewTek Inc.	v8.3	To create animation
Canon	Digital camera	Canon, inc.	EOS 5D	12.8 megapixels
Grab	Software program	Apple	v1.2	Extract texture from photographs and UV map
Adobe® Photoshop® Elements	Software program	Adobe	v3.0	Extract texture from photographs
Render Farm Commander	Software program	Bruce Rayne©	v2.9	Mass rendering across local area network
Mac Pro	Computer	Apple		Four dual processors (eight threads); Create and render animation
Sony MiniDV	Digital video recorder	Sony Corporation	GV-D300E	Playback stimuli during stimulus acquisition
Sony Trintron	Colour viewfinder	Sony Corporation	PVM-14M2A	One monitor for stimulus acquisition
Canon	Digital camcorder	Canon, inc.	MV650i	Records behavior during stimulus acquisition