Abstract: A consultation system enables a user of a lightweight client terminal (3) to interact with a three-dimensional digital model by displaying images produced in a server (2) from a detailed version of the model and displaying, during manipulation of the observation conditions, images calculated in the client terminal (3) based on coarsened data received from the server (2) and representing a simplified version of the model's geometry. The detailed images are accompanied by semantic mappings specifying, for the image pixels, an identifier of the part represented at the corresponding image location. The user designates a part in the model by indicating an image pixel and the user terminal identifies the part by referring to the semantic mapping. Parts selected by the user are highlighted by displaying over the main image either an image produced from the semantic mapping or a thumbnail calculated from the digital model.

Abstract: The sound support comprises an address track with coded words dividing the sound support into consecutive sections, each associated with a particular address. The positioning of the sound support is controlled in such a manner as to advance a section of the sound support bearing a predetermined address, to the level of a reading head. The video support comprises images, each associated with a particular address, and its positioning is controlled so as to advance in front of a projection gate an image having a predetermined address. The simultaneous running of the sound and video supports are then controlled, the speed of image projection being able to vary and being controlled according to pre-recorded instructions on a control data support, the access to which is neither related to the advance motion of the sound support nor to the image support.