Rendering is the process of generating an image from a model such as a three-dimensional terrain model by means of a computer programme. The three-dimensional terrain model to be rendered can be a grid containing elevation data, such as a Digital Elevation Model (DEM), a Digital Surface Model (DSM) or a Digital Terrain Model (DTM). The digital model may comprise data of a limited area, such as a model of a particular city or landscape, as well as a model of a continent or even a complete planet.
Computer rendering of three-dimensional terrain images is generally known from prior art: U.S. Pat. No. 7,551,172 B2 discloses a method for sending information representing three-dimensional images over a network, and U.S. Pat. No. 6,496,189 B1 discloses a method and apparatus for displaying images of an area as seen from an interactively chosen viewpoint on a remote device.
When visualizing three-dimensional terrain data of a given surrounding in a computer, for instance in a bird's view perspective, it would be desirable to simultaneously visualize available panorama images of the same surrounding, as this could provide a more convenient and detailed perception of the local conditions to a user.
US 2013/0335446 A1 discloses a method for rendering a portion of a map together with a field-of-view image from a user-selected point of the map. Other known applications such as “Google Street View” or “Bing Streetside” allow the user entering a panorama view mode from a map view mode, showing a panorama image of the same surrounding.
However, it would be advantageous to be able to watch the panorama image or a preview thereof together with the map view and oriented to a coordinate reference system of the map.