virtual agents Papers

Over the past decade, motion capture data has become a popular research tool, and motion databases have grown exponentially. Indexing, querying, and retrieving data has thus become more difficult, and has necessitated innovative approaches to using these databases. Our aim is to make this approach feasible for virtual agents signing in French Sign Language (LSF), taking into account the semantic information implicitly contained in language data. We thus structure a database in two autonomous units,... Read more

Embodied agents are a powerful paradigm for current and future multimodal interfaces, yet require high effort and expertise for their creation, assembly and animation control. Therefore, open animation engines and high-level control languages are required to make embodied agents accessible to researchers and developers. In this paper, we present EMBR, a new realtime character animation engine that offers a high degree of animation control via the EMBRScript language. We argue that a new layer of... Read more

This paper describes the design and implementation of a virtual agent that is capable of providing customers in a 3D online shop with advice. Based on a product knowledge base, a conversation model and a model of the shop, the agent communicates with the customer through text based dialogues and leads the customer through the virtual world using gestures. Read more

Enabling virtual agents to quickly and accurately infer users' psychological characteristics such as their personality could support a broad range of applications in education, training, and entertainment. With a focus on narrative-centered learning environments, this paper presents an inductive framework for inferring users' psychological characteristics from observations of their interactions with virtual agents. Trained on traces of users' interactions with virtual agents in the environment, psychological user models are induced from the interactions to accurately... Read more

Computational modeling of emotion, physiology and personality is a major challenge in order to design believable virtual humans. These factors have an impact on both the individual behavior and the collective one. This requires to take into account the empathy phenomenon. Furthermore, in a crisis simulation context where the virtual humans can be contaminated by radiological or chemical substances, empathy may lead to placebo or nocebo effects. Stemming from works in the multi-agent systems domain, our... Read more

Psychology suggests highly synchronized expressions of emotion across different modalities. Few experiments jointly studied the relative contribution of facial expression and body posture to the overall perception of emotion. Computational models for expressive virtual characters have to consider how such combinations will be perceived by users. This paper reports on two studies exploring how subjects perceived a virtual agent. The first study evaluates the contribution of the facial and postural expressions to the overall perception... Read more

With the increase in the development of autonomous agents, there is a bigger demand on their capability of interacting with other agents and users in ways that are natural and inspired by how humans interact. However, cultural aspects have been largely neglected so far, even though they are a crucial aspect of human societies. Our goal is to create an architecture able to model cultural groups of agents with perceivable distinct behaviour. In particular, this... Read more

Many researchers associate a culture with some form of knowledge; other scholars stress the importance of the environment inhabited by the knowledge carriers; while archaeologists learn about cultures through the objects produced in the environment as a result of utilizing this knowledge. In our work we propose a model of virtual culture that preserves the environment, objects and knowledge associated with a certain culture in a 3D Virtual World. We highlight the significance of virtual... Read more

We introduce a physically-based facial animation system for natural-looking emotional expressions. Our system enables creation of simple facial expressions using Facial Action Coding System (FACS) and complex facial expressions by blending existing expressions. We propose a method for blending facial actions, based on a parameterization that combines elements of FACS and MPEG-4 standard. We explore the complex expression space by examining the blends of basic emotions produced with our model. Read more

Displaying facial motions such as crying or laughing is difficult to achieve in real-time simulations and games. Not only because of the complicated simulation of the physical characteristics such as muscle motions or fluid simulations, but also because one needs to know how to control these motions on a higher level. In this paper, we propose a method that uses the MPEG-4 Facial Animation standard to control a realistic crying face in real-time. The tear... Read more