Abstract: A technique is provided for transmitting a roof structure for constructing a three-dimensional representation of a building, via a communication network. The technique is based on the transmission of an ordered list of at least two roof models, each including at least: one type of roof; one maximum height parameter of the roof. During construction of the three-dimensional representation of a building, the maximum height parameter of a roof of the list determines a base of the roof in accordance with the list, so that the roof structure corresponds to the ordered superimposition of the roods of the list.

Abstract: A technique is provided for transmitting a roof structure for constructing a three-dimensional representation of a building, via a communication network. The technique is based on the transmission of an ordered list of at least two roof models, each including at least: one type of roof; one maximum height parameter of the roof. During construction of the three-dimensional representation of a building, the maximum height parameter of a roof of the list determines a base of the roof in accordance with the list, so that the roof structure corresponds to the ordered superimposition of the roods of the list.

Abstract: The present invention sets out to combine a calculation of visibility from a viewpoint, with the selection of a level of detail for each of the nodes in a tree representing the geometry of the objects in a scene, so as increase the level of geometric detail of the visible objects and to reduce this level for all the obscured objects.

Abstract: A method and apparatus are provided for transmitting content display data between a server and at least one client terminal, whereby said data are arranged into nodes of a hierarchical tree including at least one parent node and at least one son node, a displayable element being associated with each node. One such method includes the following steps in which: the server transmits a simplified representation of the tree to the client, said representation including, for at least some of the nodes, only information for locating the displayable element in the content to be displayed; the client terminal selects at least one node of interest from the simplified representation as a function of a criterion relating to the distance from the client to the displayable element that is associated with the node of interest in the content to be displayed; and geographical data are transmitted in order to enable said displayable element to be reconstructed for the selected nodes(s) of interest.