19.1FundamentalComponentsoftheECMMS 331
19.1FundamentalComponentsoftheECMMS
The ECMMS provides a mechanism for agents to plan and interact with the envi-
ronment in a manner that is focused not only on the typical utilitarian tasks of
locomotion but also allows for the intent of the agent’s behavior to be more be-
lievable by providing specific environmental cues to the behavioral system. What
we ideally would like to have is a system that allows for different types of agents
to interact with the environment based upon how they interpret the scene, and a
major component of understanding the environment comes from the acknowl-
edgment and the use of relative spatial orientations. To help accomplish this, the
ECMMS is composed of several elements that allow an agent to receive spatial
information about its environment: they are collision sensors and the query space.
Every model has, at its core, a fundamental, atomic component that is essentially
the enabler on which the higher-order systems are built. The ECMMS is no dif-
ferent—the collision sensor is the element that allows for information to be re-
ceived from the environment.
19.2CollisionSensors
As shown in Figure 19.2, the collision sensor is a simple primitive that acts as a
callback mechanism that is triggered when specific collisions are registered with
it. As we mention below, the individual pieces of collision geometry are assigned
to a collision layer. The significance of the collision layer is that it allows for an
agent to detect surfaces that may be of interest to it—behavioral interest. Gibson
[1986] defines an affordance as “what it offers an animal, what it provides,”
where “it” is an object. This important quote can be attributed to our system be-
cause it means that just because our collision sensor receives a callback about an
overlap with some object, it doesn’t mean we need to interact with it, just that it’s
available for possible interaction. What helps us determine whether we want to
Figure 19.2. A top view of a bird with one collision sensor. When an object overlaps
with the collision sensor, a callback is invoked to register the object with the agent.
Generates callbac