摘要 |
PROBLEM TO BE SOLVED: To realize the real expression of reflection of light from a light source in a reflection area with less processing load. SOLUTION: A reflection permissible flag RF showing the permission of reflection arithmetic processing or not is set for dots of a map 30. A reflection area 20 is set in accordance with a light source position P0 and a view point position VP for reflection arithmetic processing for dots where the RF is 1. Dots are pointed where the RF is totally 0 on a land and the RF is 1 in a sea. When a frame image is written in a frame buffer, the RF is written in dots of the frame buffer, and the deformation of image information due to fluoroscopic transformation is utilized for expressing the glitter of a seal level. The width and brightness of the reflection area 20 is controlled in response to the incident angle (elevation α) of light. A reflected image object is set at a position where the position in face symmetry with the light source position on a map surface is fluoroscopically transformed on a screen and the reflected image object is superposed on the frame image. The contour and brightness distribution of the reflected image object is fluctuated with the passage of time. |