Abstract: In a rendering device Urend1, a processor 1 receives object data Dpol which defines a polygon by shape, and object data Dlin which defines a line by shape. The processor 1 also receives mesh data Dms which specifies a three-dimensional mesh representing a shape of a ground surface. Based on thus received object data Dpol and the mesh data Dms, the processor 1 generates intermediate data Dlm3 which represents the polygon mapped onto the three-dimensional mesh. Further, based on the received object data Dlin and the mesh data Dms, the processor 1 draws the shape of the line on the three-dimensional mesh so that display image data Ddisp which can display a three-dimensional image including the polygon and line drawn on the ground surface is generated. In this manner, realized is the rendering device Urend1 capable of generating the display image data having no deformation on lines when displayed.

Abstract: A polygon rendering device Urend carries out a polygon division process, in step S36, for generating, based on polygon data which specifies a polygon to be rendered, a plurality of partial polygon data each specifying one piece of partial polygons which are obtained by dividing the polygon. Then in step S37, a rendering process is performed based on the partial polygon data generated in step S36 so as to generate image data which represents an image of the polygon. Here, each of the partial polygons includes a plurality of triangles which respectively include a vertex of the polygon, and each of the triangles included in each of the partial polygons shares at least one edge with any one of the triangles included in the same partial polygon. In such a manner, the polygon rendering device Urend can render polygons at high speeds.

Abstract: An apparatus for navigating a moving object is provided for easing the action of an operator of the moving object. The apparatus has a map data acquiring section, a current position data acquiring section, an optimum route searching section for calculating an optimum route data from the map data, a forward map data acquiring section for generating a forward map data from the current position data and the optimum route data, a route navigation symbol data drawing section for generating a route navigation symbol image from the forward map data, and a stereoscopic image displaying section for displaying a three-dimensional form of the route navigation symbol image.

Abstract: This invention relates to map displaying system, in which the reference altitude value determining means obtains a reference altitude value in accordance with the altitude data in the specific area, and the altitude data changing means performs the processing that each altitude both in the plane area and the solid area have the continuity from one area to another. And the 2-dimensional road data storage means stores the 2-dimensional ground road data and the 2-dimensional underground road data separately. Therefore, the 3-dimensional road data preparing means prepares the 3-dimensional ground road data in accordance with the 2-dimensioanl ground road data and the altitude data, while preparing the 3-dimensional underground road data in accordance with the 2-dimensional underground road data and the altitude data.