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Perception Modeling for Animation

Perception modeling for animation is concerned with:

  1. Simulating the physical and optical abilities and limitations of the animal's perception.
  2. Interpreting sensory data by simulating the results of perceptual information processing within the brain of the animal.

When modeling perception for the purposes of animation, our first task is to model the perceptual capabilities of the animal. Many animals employ eyes as their primary sense organ and perceptual information is extracted from retinal images. In an animation system, such ``retinal'' images correspond to the 2D projection of the 3D virtual world rendered from the point of view of the artificial animal's ``eyes''. However, many animals do not rely on vision as their primary perceptual mode, in which case vision models alone may not be able to appropriately capture the animal's perceptual abilities.

It is equally important to model the limitations of natural perception. Animal sensory organs cannot provide unlimited information about their habitats. Most animals cannot detect objects that are beyond a certain distance away and they usually can detect moving objects much better than static objects [Tansley1965]. If these properties are not adequately modeled, unrealistic behaviors may result.

Moreover, at any moment in time, an animal receives a relatively large amount of sensory information to which its brain cannot attend all at once. Hence there must be some mechanism for deciding what particular information to attend to at any particular time. This process is often referred to as attention. The focus of attention is determined based upon the animal's behavioral needs and is a crucial part of perception that directly connects perception to behavior.

Unfortunately, it is not at all well understood how to model animal sensory organs, let alone the information processing in the brain that mediate an animal's perception of its world. Fortunately, for the purposes of animation, an artificial animal in its virtual world can readily glean whatever sensory information is necessary to support life-like behavior by directly interrogating the world model and/or exploiting the graphics rendering pipeline. In this way, our perception model synthesizes the results of perception in as simple, direct and efficient a manner as possible.


next up previous contents
Next: Overview of the Artificial Fish's Up: Perception Modeling Previous: Perception Modeling
Xiaoyuan TuJanuary 1996