Abstract: After fillet surfaces have been generated with respect to surfaces, a joint surface is generated between the fillet surface. New fillet surfaces are determined from the fillet surfaces and the joint surface. Then, a phase relationship is established between data relative to the surfaces and data relative to the new fillet surfaces, and these data are combined into shape data including data of fillet surfaces which are capable of representing the complete shape of a product.

Abstract: A method of and an apparatus for producing solid models, in which input data consisting of the coordinates of terminal points and a formula of a curved line of each arc of a given wire frame model is read. The coordinates of a node and a set of arcs connected thereto are determined based on the input coordinates of the terminal points. A set of arcs looping around an indivisible surface of the wire frame model are specified as the outermost line surrounding the whole wire frame model. A region of the wire frame model surrounded by the outermost line or division lines is divided into two new partial wire frame models by a new division line starting from a node located on the outermost line or the division lines, traversing the region without making a loop, passing along each of the arcs included in the region only once, and reaching another node located on the outermost line or the division lines.