Plotting method, plotting program, and plotting equipment

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;
• and
• 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.

A computer-readable recording medium that stores therein a computer program making a computer execute:

• 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;
• and
• 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.

A drawing apparatus comprising:

• an input unit configured to input arbitrary view point coordinates in a three-dimensional coordinate system;
• a first drawing unit configured to draw 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;
• a modifying unit configured to modify 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;
• and
• a second drawing unit configured to draw, 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.