Assistance à l'interaction Homme-Molécule in virtuo: application au chromosome. (Assistance to the human-molecule interaction : application to the chromosom)

One of the aims of Molecular Biology (MB) is the study of the molecules’ 3D structure. In silico experiments (ie. computing simulations) for 3D modeling usually use automatic approaches. However, these approaches have limits : important computing time, local modeling, 3D model generally fixed, etc. The contribution of expert knowledge, interactively during the automatic modeling process, can overcome some limits of the usual computational methods. It involves placing the biologist in the center of virtual experiments, rather than an observer of automatic simulation results. This is what we call hybrid approach, that combines the advantages of in silico experiments and those of Human-Computer Interaction (HCI) and Virtual Reality (VR) : natural interaction, immersion in the virtual environment (VE), multimodality, etc. The result of this approach is the creation of in virtuo experiments which has three components : the 3D modeling, the visualization and the 3D interaction (3DI). However, complex domains such as MB are governed by several constraints that may be local (linked to 3D objects or 3DI techniques) or global (linked to virtual environment or to the 3DI system). Therefore, experts intervention can not be efficiently realized by conventional 3DI techniques, without taking into account the domain complexity (ie. constraints). More generally, we are confronted to the problem of constrained 3DI which includes behavior rules imposed by the VE. The solution we propose is an assistance model that associates constraints, interaction task and assistance tools. The assistance tools are Virtual Fixtures. We applied these two concepts, hybrid approach and assistance model, to the chromosome 3D modeling. The identified constraints are architectural (ie. physico-chemical data) and functional (ie. biological models). These biological constraints dictate the chromosome spatial organization. The in virtuo Human-Molecule interaction system can be considered more credible because it respects the environment constraints, both in the 3D structure and at the level of 3DI.