THREE-DIMENSIONAL-MAP DISPLAY SYSTEM

[Object] To display a 3D map representing a feature that cannot be visually recognized such as an underground structure without a sense of discomfort. [Solution] With respect to features stored in the map database, an underground structure such as a tunnel are classified into a transmissive object, and other features into a non-transmissive object. Then, a transmissive object and a non-transmissive object are projected individually so as to generate a transmissive object projection view and a non-transmissive object projection view. The transmissive object projection view thus obtained is superposed on the non-transmissive object projection view with adjusted transmittance. Making the transmissive object to be transmissive and superposing it enables to realize a map that appears to the user as if a ground surface or a feature which has shielded the transmissive object is made to be transmissive whereby the transmissive object come to be visible.