三面図から曲面を含む立体の自動生成  [in Japanese] Automated Construction of Solid Objects with Curved Surfaces from Orthographic Three-View Drawings  [in Japanese]

Since the development of the revolutionary SKETCHPAD system developed by Ivan E. Sutherland, many works have been done on the automatization and systemization of machine design and machine draughting processes through the application of computers. At present, computer draughting is well established and most widespread in industry. However, the representation remains strictly two-dimensional and the computer has no understanding of the three-dimensional geometry or the physical properties of the object which lies behind the drawing. Not a few works have been done on the understanding and construction of polyhedral objects from usual orthographic three views. However, these works cannot be applied to the drawing of mechanical parts, because real mechanical parts are composed of curved surfaces as well as flat ones. In this paper, we present an algorithm which can represent all solid objects with curved surfaces satisfying orthographic three-view drawings. The algorithm for the construction of polyhedral objects is modified by introducing the cubic Bezier curves and the bicubic Bezier surfaces. This new algorithm has been implemented and has functioned well on complex objects with curved surfaces.