Abstract: Techniques for displaying a 3d map view of a 3d geographical map are provided. A database stores data which defines the 3d geographical map in a layered hierarchy comprising data layers which can be individually rendered for the 3d map view. The database comprises a data layer of a digital terrain model which is modelling a terrain surface and a data layer of a 3d road network comprising 3d road elements. A processor is configured for selecting specific data layers of the database in response to a resolution setting of the 3d map view and to render the 3d map view using the selected specific data layer.

Abstract: A navigation device for a vehicle comprises a database storing, for a plurality of tiles of a tiling, at least one triangulated irregular network (TIN) defining a three-dimensional surface, and, for a plurality of triangular faces of the at least one TIN, control information defining a nested bounding sphere for the respective triangular faces. The navigation device comprises a processor coupled to the database configured to calculate a screen-space error for the plurality of triangular faces based on the respective control information and based on at least one of the following: a viewing angle of an electronic map view, a virtual camera position of the electronic map view. The processor is configured to predict whether a triangular face is visible in the electronic map view based on the calculated screen-space error.

Abstract: A navigation device comprises a processing device and a database. The database may store first data defining, for a plurality of objects, respectively a three-dimensional representation of the object. The database may store second data including, for at least a subset of the plurality of objects, an icon representation of the respective object, coordinates of the respective object and a pointer to a portion of the first data which is associated with the respective object. The processing device is coupled to the database and is configured to control an optical output device to display an object based on the first data or based on the second data.

Abstract: The invention relates to system and method for generating a 3-dimensional representation of a tunnel. Road network data is provided having a plurality of road segments, at least one road segment being a tunnel road segment, including the information that said at least one road segment is a road segment located in a tunnel. The tunnel segment in the road network is identified, providing a geographical elevation map including elevation data of the geographical region in which the tunnel road segment is located, providing predefined patterns representing predefined parts of a 3-dimensional tunnel body, generating the 3-dimensional representation of the tunnel based on the tunnel road segment, the elevation map and the predefined patterns, and storing the 3-dimensional representation of the tunnel in connection with the road network as a 3-dimensional object which is located at the geographical position of the tunnel road segment.

Abstract: Techniques for displaying a 3d map view of a 3d geographical map are provided. A database stores data which defines the 3d geographical map in a layered hierarchy comprising data layers which can be individually rendered for the 3d map view. The database comprises a data layer of a digital terrain model which is modelling a terrain surface and a data layer of a 3d road network comprising 3d road elements. A processor is configured for selecting specific data layers of the database in response to a resolution setting of the 3d map view and to render the 3d map view using the selected specific data layer.

Abstract: A difference file which indicates a difference between a second relational database and a first relational database may be transferred to a navigation device. The navigation device may store a first compressed database version of the first relational database. The navigation device may restore database pages of the second relational database based on the first compressed database version and the difference file. The restoration may be performed on per-page level. The restoration may involve reading and uncompressing a database page from the first compressed database version, and modifying the uncompressed database page in accordance with the difference file. The modified database page, which may correspond to a restored page of the second relational database, may be compressed and appended to a target database.

Abstract: A navigation device comprises a processing device and a database. The database may store first data defining, for a plurality of objects, respectively a three-dimensional representation of the object. The database may store second data including, for at least a subset of the plurality of objects, an icon representation of the respective object, coordinates of the respective object and a pointer to a portion of the first data which is associated with the respective object. The processing device is coupled to the database and is configured to control an optical output device to display an object based on the first data or based on the second data.

Abstract: The invention relates to system and method for generating a 3-dimensional representation of a tunnel. Road network data is provided having a plurality of road segments, at least one road segment being a tunnel road segment, including the information that said at least one road segment is a road segment located in a tunnel. The tunnel segment in the road network is identified, providing a geographical elevation map including elevation data of the geographical region in which the tunnel road segment is located, providing predefined patterns representing predefined parts of a 3-dimensional tunnel body, generating the 3-dimensional representation of the tunnel based on the tunnel road segment, the elevation map and the predefined patterns, and storing the 3-dimensional representation of the tunnel in connection with the road network as a 3-dimensional object which is located at the geographical position of the tunnel road segment.