2009 Papers

Coming to open domain dialog it is still unrealistic to implement needed knowledge resources and dialog skills linguistically. Since the Non Player Characters (NPC) in our NPC Engine should be capable of open conversation we decided to use an Artificial Intelligence Markup Language (AIML) [1] chatbot as a first workaround. However AIML chatbots are not linguistically motivated, they use surface structures in tradition of Weizenbaums ELIZA [2], wherefore they do have too many shortcomings to... Read more

Virtual humans are employed in many interactive applications, including (serious) games. Their motion should be natural and allow interaction with its surroundings and other (virtual) humans in real time. Physical controllers offer physical realism and (physical) interaction with the environment. Because they typically act on a selected set of joints, it is hard to evaluate their naturalness in isolation. We propose to augment the motion steered by such a controller with motion capture, using a... Read more

Video game technology now enables a new set of experiences for players in addition to conventional video games. Although the intensity of the technological research in this field is shifting from graphics to AI design and characters with embodied agents [1], there have been few studies involving the assessment of real-time sequential, emotional changes of video-game players. Research of this issue and the implications may assist in preventing game addiction and decreasing one's zest for... Read more

In this paper, a new low-dimensional motion model that can parameterize human motion style is presented. Based on this model, a human motion synthesis approach by using constrainted optimization in a low-dimensional space is proposed. We define a new inverse kinematics solver in this low-dimensional space to generate the required motions meeting user-defined space constraints at key-frames. Our approach can also allow users to edit motion style explicitly by specifying the style parameter. The experimental... Read more

This paper presents an architecture for an intelligent virtual agent that imitates human drumming behaviour. Through imitation, the agent models the user-specific variations that constitute the "groove" of the drummer. The architecture comprises a motor system that imitates arm movements of a human drummer, and a sound system that produces the sound of the human playing style. The presence of a sound system alleviates the need to use physical models that will create sound when... Read more

Interactive Virtual Standardized Patients (VP) can provide meaningful training for clinicians. These VP's portray interactive embodied conversational characters with realistic representations of a mental or physical problem to be diagnosed or discussed. This research is a continuation of evaluating of our VP "Justina" [2] which suffers from Posttraumatic Stress Disorder (PTSD) from a sexual attack and presents the results of comparing novices, test subjects without medical training, and experts interacting with 'Justina' to find out... Read more

Basic communication and coordination mechanisms of human social interaction are assumed to be mediated by perception-action links. These links ground the observation and understanding of others in one's own action generation system, as evidenced by immediate motor resonances to perceived behavior. We present a model to endow virtual embodied agents with similar properties of embodied perception. With a focus of hand-arm gesture, the model comprises hierarchical levels of motor representation (commands, programs, schemas) that are... Read more

Recent studies have shown that virtual humans can facilitate social interactions among people who have difficulty in forming social bonds or help develop their social skills by interaction with virtual practice. Virtual human research tends to focus exclusively on appearance or behavior in assessing agent effectiveness, whereas other studies of human social interaction emphasize aspects of the social context, such as anticipated future interaction (AFI) which has been implicated as a key moderator of people's... Read more

Expressing spatial information with iconic gestures is abundant in human communication and requires to transform a referent representation into resembling gestural form. This task is challenging as the mapping is determined by the visuo-spatial features of the referent, the overall discourse context as well as concomitant speech, and its outcome varies considerably across different speakers. We present a framework, GNetIc, that combines data-driven with model-based techniques to model the generation of iconic gestures with Bayesian... Read more

We propose a computational model for building a tactile body schema for a virtual human. The learned body structure of the agent can enable it to acquire a perception of the space surrounding its body, namely its peripersonal space. The model uses tactile and proprioceptive informations and relies on an algorithm which was originally applied with visual and proprioceptive sensor data. In order to feed the model, we present work on obtaining the nessessary sensory... Read more