| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a three-dimensional map drawing system maintaining a reduced scale. <P>SOLUTION: Feature data three-dimensionally drawing a feature such as a road or building is preliminarily prepared, and a three-dimensional map is drawn based on the data. The feature data is generated not by perspective projection but by a method for projecting a real feature CST2 to a projection plane PL2 by parallel lines laid along a projection direction PRJ or parallel projection. The feature data is prepared by two-dimensional raster or polygon data drawing a parallel-projected projection view. Only by drawing the thus-prepared feature data, the three-dimensional map can be drawn without processing with high load such as rendering. Since a positional relation between buildings or a reduced scale of shape are maintained in the parallel projection, differed from the perspective projection, the three-dimensional map maintaining the reduced scale can be provided. <P>COPYRIGHT: (C)2011,JPO&INPIT |
