Introduction

Figure 1.1 depicts a computer character situated in some virtual world. More precisely, it shows one of the dinosaur characters that we will meet later on in one of our case studies. For now, the specifics of the particular character are not important; all we need to notice is the balloon overhead. The balloon is meant to represent what is inside the character’s head. In particular, we can see that the character possesses its own internal model of its virtual world. We refer to a character’s internal model of its world as a cognitive model. Cognitive models are applicable to controlling the new breed of highly autonomous, quasi-intelligent characters that are beginning to find use in animation and game production. Cognitive models are what this book is all about; they govern what a character knows about its world, how that knowledge is acquired, and how it can be used to select actions.