A paradigm for controlling virtual humans in urban environment simulations

Presents a new architecture for simulating virtual humans in complex urban environments. The approach is based on the integration of six modules. Four key modules are used in order to manage environmental data, simulate human crowds, control interactions between virtual humans and objects, and generate tasks based on a rule-based behavioral model. The communication between these modules is made through a client/server system. Finally, all low-level virtual human actions are delegated to a single motion and behavioral control module. Our architecture combines various human and object simulation aspects, based on the coherent extraction and classification of information from a virtual city database. This architecture is discussed in this paper, together with a detailed case study exampl

Germline bias dictates cross-serotype reactivity in a common dengue-virus-specific CD8(+) T cell response.

Adaptive immune responses protect against infection with dengue virus (DENV), yet cross-reactivity with distinct serotypes can precipitate life-threatening clinical disease. We found that clonotypes expressing the T cell antigen receptor (TCR) β-chain variable region 11 (TRBV11-2) were 'preferentially' activated and mobilized within immunodominant human-leukocyte-antigen-(HLA)-A*11:01-restricted CD8(+) T cell populations specific for variants of the nonstructural protein epitope NS3133 that characterize the serotypes DENV1, DENV3 and DENV4. In contrast, the NS3133-DENV2-specific repertoire was largely devoid of such TCRs. Structural analysis of a representative TRBV11-2(+) TCR demonstrated that cross-serotype reactivity was governed by unique interplay between the variable antigenic determinant and germline-encoded residues in the second β-chain complementarity-determining region (CDR2β). Extensive mutagenesis studies of three distinct TRBV11-2(+) TCRs further confirmed that antigen recognition was dependent on key contacts between the serotype-defined peptide and discrete residues in the CDR2β loop. Collectively, these data reveal an innate-like mode of epitope recognition with potential implications for the outcome of sequential exposure to heterologous DENVs

Virtual human life simulation and database: why and how

In combination with the rapid technical improvements of computers, building large virtual scenes has become a popular field in computer graphics. Often, within a real reconstructed city, a building that has disappeared, or a virtual town, virtual humans populating these scenes are expected to provide a feeling of real life. Our specific aim is to populate these scenes with virtual humans in order to offer assistance in decision making concerning urban infrastructures. In this view, we have to integrate the problem of planning human actions and behaviour for urban life simulation into a virtual town. We present an informed environment, which corresponds to a database dedicated to urban life simulation. We discuss the use of a database, and methods and tools for creating and providing the information necessary for animating virtual humans in a city. The informed environment is based on the hierarchical decomposition of an urban scene into environment entities providing geometrical information as well as semantic notions, thus allowing a more realistic simulation of humans. In this manner, virtual humans can be provided with a certain kind of urban knowledge. Moreover, the database can offer other types of services for scene creation for exampl

An Informed Environment dedicated to the simulation of virtual humans in urban context

We outline the creation of an Informed Environment, dedicated to urban life simulation. We propose methods and tools for creating and providing the information necessary for animating virtual humans in a city using an Informed Environment. The Informed Environment is based on a hierarchical decomposition of an urban scene into Environment Entities providing geometrical information as well as semantic notions, thus allowing a more realistic simulation of human behaviour. In this manner, virtual humans can integrate with a certain kind of urban knowledg

Database and modelling strategy: a compliant way for display optimisation

In order to display huge scenes with virtual human inhabitants evolving inside a virtual city, we propose a methodology to create and manage different levels of detail for a well-segmented scene without ”re-meshing” the scene during simulation. A database dedicated to urban life simulation, providing data for planning human actions and behaviour, is completed such a way to furnish information about the most adapted displayed representation