| 摘要 |
PROBLEM TO BE SOLVED: To provide a three-dimensional drawing system and a program therefor capable of shifting by easy operation to a state in which a surface obtained from a perspective state is viewed from the front.SOLUTION: A three-dimensional drawing system comprises a front view tool for displaying in response to an input operation a front view plane of a specific surface of an object contained in graphic data. The front view tool comprises: operation detection means for detecting the content, quantity, and direction or coordinates of the input operation; object detection means for identifying an object intersecting or approaching a normal to the plane at the time of the input operation; oblique angle determination means for detecting the specific vector of which intersecting angle with the normal to the plane during the input operation is equal to or less than a predetermined angle, from among the vectors of the object identified by the object detection means; and rotation means for rotating relative to the line of vision an edition space containing the graphic data according to the information detected by the operation detection means and also rotating relative to the line of vision the edition space containing the graphic data such that when the specific vector is detected at termination of the input operation, the specific vector becomes parallel to the normal to the plane. |
