Towards Virtual Actors - The Next Step for the Entertainment Industry Rog´ erio E. da Silva University of Minho Guimar˜ aes, Portugal Santa Catarina State University Joinville, Brazil Ido A. Iurgel University of Minho Guimar˜ aes, Portugal Manuel F. dos Santos University of Minho Guimar˜ aes, Portugal Figure 1: CREACTOR Animation Tool interface Abstract Autonomous Digital Actors (ADA) represent the next step for the entertainment industry in the sense that they are new kind of virtual characters endowed with self-animation capabilities delivered by artificial intelligence techniques. There are many substantial open questions related to the development of virtual actors. This article introduces the subject ‘virtual actors’ and describes an experimental authoring tool, called CREACTOR. We are developing this tool for studying which AI techniques can be used to design and implement behaviors of ADAs. Keywords:: Interactive Storytelling, Computer Animation, Be- lievable Characters, Virtual Actors Author’s Contact: rsilva@joinville.udesc.br, idoiurgel@yahoo.de, mfs@dsi.uminho.pt 1 Introduction In [Perlin and Seidman 2008], the authors foresee that “3D ani- mation and gaming industry will soon be shifting to a new way to create and animate 3D characters, and that rather than being re- quired to animate a character separately for each motion sequence, animators will be able to interact with software authoring tools that will let them train an Autonomous Digital Actor (ADA) how to employ various styles of movement, body language, techniques for conveying specific emotions, best acting choices, and other general performance skills.” Our ongoing research aims at developing virtual actors. Virtual ac- tors are a kind of believable characters [Reilly 1996]. A virtual actor is an analogy to a real actor, which autonomously, and by its independent interpretation of the situation, can perform its role ac- cording to a given script, as part of a story [Iurgel and Marcos 2007; Iurgel 2008]. Virtual actors must exhibit a behavior similar to real actors, which means, they must be able to play roles specified according to guide- lines; but also they must be able to use their own previous expe- riences, adapting their performance to new contexts. Besides that, they should also be capable of understanding abstract commands from a director/animator who could inform them about desired be- haviors in a particular situation. The ability of characters to improvise and get guidelines from a director represents a new approach on authoring characters for the production of 3D-movies. Through this new approach, it should be possible to speed up the process of creation of animation films populated with synthetic characters, because those characters are able to decide about most of the acting performance by themselves, reducing the time and effort needed for animation. We are developing an authoring framework, called CREACTOR (see figure 1), that is an experimentation platform for exploring different solutions and processes. The actors are implemented as talking heads. CREACTOR focuses on providing a broad number of features and modules that are at first implemented in a shallow way. Future steps shall then identify the most important dependen- cies and possible enhanced solutions on the level of the modules. The expectation is that this kind of tool will simplify the authoring process in such a way that unskilled animators will be able to create 3D animations with a higher quality than current animation tools allow. 2 Virtual Actors A real actor is someone capable of expressing dramatic actions (the- atrical skills) based on a script. A virtual actor is a believable char- acter capable of understading its role from an annotated script and, by interpreting the situation, to propose an appropriate behavior (acting performance) for it. This performance could then be cor- rected/improved by the animator. Next sections aim at explaining our actors/humans metaphor, how acting students learn how to act (this process had inspired us to propose our method for creating virtual actors), and then how to implement virtual actors. 2.1 (Virtual) Actors vs. (Virtual) Humans An actor has abilities that a normal person does not have, for in- stance, an actor can play a role. Virtual humans are, according to Thalmann & Thalmann [Thal- VIII Brazilian Symposium on Games and Digital Entertainment Rio de Janeiro, RJ – Brazil, October, 8th-10th 2009 105