Consulting digital models from lightweight terminals

A user terminal for consultation of a three-dimensional digital model, the user terminal comprising a display unit and a user interface enabling the user to define the observation conditions to be used when displaying the digital model and to define a scene corresponding to a subset of the parts making up the digital model, wherein the user terminal further comprises:

• receiver means adapted to receive from a server by means of a communications link:
• image data defining a detailed image of the scene specified via the user interface, the image data being calculated under the observation conditions defined by the user interface;
• and
• coarsened data defining said scene according to a simplified geometry;
• the display unit being adapted to display a detailed image of said scene on the basis of the detailed image data received from the server;
• and
• calculation means adapted to calculate image data representing said scene during a change of observation conditions, on the basis of said coarsened data received from the server.

A computer program product for implementing consultation of a three-dimensional digital model via a communications link, the product comprising instructions for performing the following steps on being executed:

• inputting an instruction coming from a user indicating the observation conditions to be employed while displaying the three-dimensional digital model, and defining a scene corresponding to a subset of the set of parts of the digital model;
• receiving from a server and via the communications link:
• detailed image data defining a detailed image of the scene defined by the user and displayed under observation conditions defined by the user, the image data being calculated from data defining the three-dimensional digital model according to a detailed geometry;
• and
• coarsened data defining said scene using a simplified geometry;
• calculating image data representing said scene during a change of observation conditions, on the basis of coarsened data received from the server;
• and
• displaying the image data produced during the calculation step.

A computer program product for enabling a three-dimensional digital model to be consulted by a client terminal, the product comprising instructions for performing the following steps on being executed:

• receiving a request from a client;
• and
• supplying data to the client in order to response to the request;
• wherein the product further includes instructions for performing the following steps, on being executed;
• accessing data defining the three-dimensional digital model according to a detailed geometry;
• using said data defining the digital model using detailed geometry to calculate image data defining a detailed image of a scene defined by a client and viewed under observation conditions defined by the client, said scene corresponding to a subset of the parts of the digital model selected by the client;
• and
• transmitting to the client:
• said detailed image data;
• and
• coarsened data defining said scene using si