| 摘要 |
PROBLEM TO BE SOLVED: To improve visibility of a linear object such as a road when a three-dimensional map is displayed by a bird's eye view.SOLUTION: In three-dimensional map data, polygon data representing a three-dimensional shape is stored with regard to a building and the like, and line data is stored with regard to a linear object such as a road and a rail track. When the three-dimensional map is displayed by a bird's eye view, first, the polygon data is generated with a width given to the line data with regard to the linear object. Then, a polygon PP and a line LL are superposed all over the linear object to be displayed. Thus, in the area of this side close to a view point, the linear object can be displayed by increasing the perspective by the polygon PP, and in the area of a great distance, the linear object can be displayed in a state that minimum width is secured by the line LL, and therefore, the visibility of all over the linear object can be improved. |
