Summary

This chapter looked at the different levels at which emotions affect the animat:

• Sensations are reactions to patterns that trigger changes in the emotions, generally based on perceptions.

• Emotions are persistent characteristics of a creature's state.

• Feelings are emotions associated with arbitrary objects.

• The latter sections defined an interface for communicating the emotions from the AI to the engine, so that they can be portrayed within the game by animation technology.

A dedicated interface for emotions has many advantages thanks to the separation of the emotions with the behaviors.

Existing actions as well as the new gesture and text interfaces remain independent of emotions, and the AI can assume the engine does its best to display the emotions.

Finite state machines are discussed in the next chapter, which focuses on the theory. Chapter 39, "Under the Influence," applies finite state machines to model the emotional state, and discusses the role of the sensations in influencing the emotions.

Practical Demo Actor is an animat with a large database of actions and mannerisms that reveal emotions. Actor is content using these gestures arbitrarily, and does not attempt to use them meaningfully within the context. Each mannerism is implemented with a previous AI technique—as appropriate.