SYSTEM FOR EXTRACTING THREE-DIMENSIONAL COORDINATE FROM TWO-DIMENSIONAL PERSPECTIVE DRAWING

摘要

PURPOSE:To extract three-dimensional coordinate data at high speed and exactly from a two-dimensional perspective drawing by deriving a reverse perspective conversion by using a rectangular parallelepiped. CONSTITUTION:By a reverse perspective conversion processor 3, a rectangular parallelepiped 8 can change freely length of three sides, and also, based on a perspective conversion, a parameters such as a position of a visual point, an eye direction, a position of a plane of projection, etc. can be changed freely. The rectangular parallelepiped 8 obtained in such a way and image data 7 are superposed and displayed, an when a length change of three edge lines and a free perspective conversion are added to the rectangular parallelepiped by the reverse perspective conversion processor 3, the edge line of the rectangular parallelepiped 8 can be allowed to coincide with the edge line of the image data 7. A rectangular parallelepiped 9 shows a rectangular parallelepiped which has coincided in such a way. The determination of the rectangular parallelepiped 9 is equivalent to a fact of deriving a reverse perspective conversion of the image data 7, therefore, when a deriving a reverse perspective executed by various parameters of the perspective conversion which is derived at this time, the image data 7 can be handled as if it is three-dimensional shape data.