Pathematic agents: rapid development of believable emotional agents in intelligent virtual environments

Intelligent Virtual Environments have grown considerably over the past few years. This paper presents an architecture for building Believable Emotional Agents, (which we call Pathematic’ Agents) in Intelligent Virtual Environments and describes part of its implementation. The architecture follows a theatrical metaphor and is divided in three modules: the dynamic script-writer (mind module), the theatrical company with its director and cast of actors (body module) and the actual settings where the action takes place (world module). The paper concentrates on the mind module implementation. The mind module uses the cognitive theory of emotions of Ortony, Clore and Collins to handle the emotion structures of the virtual agents and is inspired on Fridja’s two-stage emotional stimuli appraisal theory. This paper also describes the integration of the mind module in a real time application implementing the presented architecture. The application was exhibited in Lisbon, in the Territory Pavilion of the last world exposition of the century: Expo’98. Two synthetic dolphins, Trist* and Isolda, the main characters of this Intelligent Virtual Environment lived during the four months of the exposition and were displayed to more than one million visitors. The project was implemented under a tight schedule and showed that the architecture implementation is a viable solution for short time de velopment of quality Intelligent Virtual Environments. lPathematic: (a. ram (ad. GR.) pathematicoe liable to pandon or emotiona, s. pathema what one sufk, mEering emotions, s. stem path -me pathetic) pertaining to the pamsims or emotions; camnd or charactesised by emotions. (Oxford Eh@nh Dictionary) Thin work was mpported by PRAXIS XXl BM/la597/97. Permission to make digital or hard copies of all or part ofthis work for personal or classroom use is granted without fBe provided that copies are not made or distributed fbr prolit or commercial advantage and that copies bear this notice and the full citation on the first page. -1‘0 copy otherwise. to republish, to post on servers or to redistribute to lists. requires prior specific permission and/or a fee. Autonomous Agents ‘99 Seattle WA USA Copyright ACM 1999 I-581 13-066~x199/05.,.$5.00