1. A drawing method comprising: inputting arbitrary view point coordinates in a three-dimensional coordinate system; drawing a first image of an object generated based on road network data that uses a two-dimensional coordinate system, the first image illustrating the object viewed from the view point coordinates; modifying depth information of the first image to information on distance from a position closer to the view point coordinates than a position of the object; drawing, based on modified depth information, a second image of a ground object so as to overlap with the first image, the second image illustrating the ground object viewed from the view point coordinates, the ground object expressed using the three-dimensional coordinate system, and drawing a third image of a transparent object that is present at a position closer to the view point coordinates than the position of the object, wherein the modifying includes modifying the depth information to depth information of the third image.