| 摘要 |
PROBLEM TO BE SOLVED: To make it possible to easily discriminate the correspondence of a target construction between a plan and a projected plan when changing over the plan and the projected plan. SOLUTION: In the case of switching a plan to a projected plan, a visual point setting means 5 successively changes the positions of visual points to be set up based on an instruction from a switching means 2. An intermediate projected plan plotting means 9 plots an intermediate projected plan by center projection based on an optical axis connecting a visual point set up by a visual point setting means 5 to a noticed visual point set up by a noticed visual point setting means 6 by using the contour information and shape information of a construction stored in a storage means 1 and displays the intermediate projected plan on a display means 4. |
