Interacting with virtual characters in interactive storytelling

Abstract

In recent years, several paradigms have emerged for interactive storytelling. In character-based storytelling, plot generation is based on the behaviour of autonomous characters. In this paper, we describe user interaction in a fully-implemented prototype of an interactive storytelling system. We describe the planning techniques used to control autonomous characters, which derive from HTN planning. The hierarchical task network representing a characters' potential behaviour constitute a target for user intervention, both in terms of narrative goals and in terms of physical actions carried out on stage. We introduce two different mechanisms for user interaction: direct physical interaction with virtual objects and interaction with synthetic characters through speech understanding. Physical intervention exists for the user in on-stage interaction through an invisible avatar: this enables him to remove or displace objects of narrative significance that are resources for character's actions, thus causing these actions to fail. Through linguistic intervention, the user can influence the autonomous characters in various ways, by providing them with information that will solve some of their narrative goals, instructing them to take direct action, or giving advice on the most appropriate behaviour. We illustrate these functionalities with examples of system-generated behaviour and conclude with a discussion of scalability issues.

Modeling self-efficacy in intelligent tutoring systems: An inductive approach

“…In contrast, one can imagine a much richer form of narrative learning environment that dynamically crafts customized stories for individual students at runtime. Recent years have seen the emergence of a growing body of work on dynamic narrative generation (Cavazza et al 2002;Riedl and Young 2004;Si et al 2005), and narrative has begun to play an increasingly important role in ITS (Machado et al 2001;Mott and Lester 2006b;Riedl et al 2005). Narrative experiences are powerful.…”

DIS planning algorithms evaluation

“…HTN-based planning [10], which is also known as taskdecomposition planning, is among the oldest approaches for providing domain-specific knowledge to a planning system.…”

“…I-Storytelling (a.k.a. Friends) The Interactive Storytelling approach described in [10] and [11] is character-based supporting user interventions at any time. The graphic environment of the system was based on the Unreal™ game engine and the scenario used is inspired from the popular sitcom Friends™.…”

Compelling experiences in mixed reality interactive storytelling

“…The interactive storytelling technology used in these experiments has been developed in previous work and is described in detail in [5] [6]. We shall thus only give a brief overview of the approach, insisting on those aspects that are most relevant to its Mixed Reality implementation.…”