Pour l’Obtention du grade de Docteur ès Sciences par

- ii-This thesis is about the problem of how to achieve real time virtual environments with autonomous virtual human actors, which can interact with virtual objects in order to achieve a given task. The focus is on interaction with day life objects having some proper functionality and purpose, as for example: automatic doors, general furniture, or a lift. The proposed approach is based on a complete definition and representation for interactive objects. A graphical modeler application was specifically developed in order to define such representation of interactive objects, which are called smart objects. This representation is based on the description of all interaction features: parts, movements, graspable sites, functionalities, etc. In particular, smart objects keep interaction plans for each possible actor-object interaction, detailing all primitive actions that need to be taken by both the object and the actor, in a synchronized way. Regarding the shape representation of objects, a new boundary representation data structure is introduced, providing low storage space requirements together with constant time access to adjacenc