| 摘要 |
PURPOSE:To easily input coordinates of an optional point of a three-dimensional image by drawing a ring-shaped mark obtained when a displayed sphere or hemisphere is viewed from a polar point on a tablet, and hitting a position in the ring. CONSTITUTION:The three-dimensional image of the hemisphere G is displayed on a screen 1 by a wire frame method and when a position A on the spherical shape is specified as a visual point A, a position (a) in a circle (c) on the tablet 2 is hit. When a position B on the reverse side of the hemisphere G is specified as the visual point, a position (b) in a circle (c) on the tablet 2 is hit. The hemispherical body G displayed on the screen 1 corresponds to the northern hemisphere of the earth, and the circle (c) on the tablet 2 is the ring when the hemisphere G is viewed from above the north pole and corresponds to the equator. Namely, a position image of the surface of the hemisphere G on the screen 1 is projected on the tablet 2 and a hit is only made on the tablet 2 to specify an optional position on the surface of the hemisphere G on the screen 1. |
