Abstract: A method for rendering a three-dimensional terrain, the method including providing at least one previous display pixel having a previous ray from a point of view through the at least one previous display pixel to a previous terrain unit intersecting an axis of the previous ray, the previous ray having a length, and computing a subsequent ray from the point of view through a subsequent display pixel, whereby the subsequent ray has a length equal to the length of the previous ray.

Abstract: A method of providing data blocks describing three-dimensional terrain to a renderer. The data blocks belong to a hierarchical structure which includes blocks at a plurality of different resolution levels. The method includes receiving from the renderer one or more coordinates in the terrain along with indication of a respective resolution level, providing the renderer with a first data block which includes data corresponding to the one or more coordinates, from a local memory, and downloading from a remote server one or more additional data blocks which include data corresponding to the one or more coordinates if the provided block from the local memory is not at the indicated resolution level.

Abstract: A method for rendering a three-dimensional terrain, the method including providing at least one previous display pixel having a previous ray from a point of view through the at least one previous display pixel to a previous terrain unit intersecting an axis of the previous ray, the previous ray having a length, and computing a subsequent ray from the point of view through a subsequent display pixel, whereby the subsequent ray has a length equal to the length of the previous ray.