SHAPE DATA GENERATIG METHOD

PURPOSE: To obtain a connection surface which smoothly connects with a peripheral curved surface by dividing the connection surface into three areas, and generating curved surfaces in the areas by using information on existent peripheral curved surfaces and then connecting the three curved surfaces. CONSTITUTION: Plural constitution points are set on outlines L1 and L2 according to the curvatures, etc., of outlines L1 and L2. Then, the connection surface C where the constitution points are set is divided into three areas B1 (2nd area), B2 (1st area), and B3 (3rd area). After a curved surface in the center area B1 (Bi=B1) with i=1, curved surfaces in the areas B2 and B3 (Bi=B2, B3) are generated by using curved surface information on the area B1. In this case, the difference between the shape of an outline g4 and the shape of an outline g6 is absorbed by outlines g7 and g8 constituting the center area B1 to obtain the connection surface C which smoothly connects the fillet surfaces F1* and F3*.